diff --git a/CHANGELOG.md b/CHANGELOG.md
index e61ddda..e7c0ffd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 ### Added
+- Attribute splitting if they are passed as `str` in configs, by @HardNorth
+
+## [5.6.6]
+### Added
 - Microseconds precision for timestamps, by @HardNorth
 ### Changed
 - Client version updated to [5.7.4](https://github.com/reportportal/client-Python/releases/tag/5.7.4), by @HardNorth
diff --git a/pytest_reportportal/config.py b/pytest_reportportal/config.py
index 29e56be..ba0b70b 100644
--- a/pytest_reportportal/config.py
+++ b/pytest_reportportal/config.py
@@ -23,6 +23,24 @@
 from reportportal_client.helpers import to_bool
 from reportportal_client.logs import MAX_LOG_BATCH_PAYLOAD_SIZE
 
+ATTRIBUTES_SEPARATOR = ";"
+
+
+def normalize_attributes(attributes: Optional[Any]) -> Optional[Any]:
+    """Split a string of attributes into a deduplicated list of attributes."""
+    if not attributes:
+        return attributes
+    if not isinstance(attributes, str):
+        return attributes
+    normalized_attributes = []
+    unique_attributes = set()
+    for attribute in attributes.split(ATTRIBUTES_SEPARATOR):
+        attribute = attribute.strip()
+        if attribute and attribute not in unique_attributes:
+            unique_attributes.add(attribute)
+            normalized_attributes.append(attribute)
+    return normalized_attributes
+
 
 class AgentConfig:
     """Storage for the RP agent initialization attributes."""
@@ -115,8 +133,8 @@ def __init__(self, pytest_config: Config) -> None:
             )
         self.rp_launch_uuid = self.find_option(pytest_config, "rp_launch_uuid", self.rp_launch_uuid)
 
-        self.rp_launch_attributes = self.find_option(pytest_config, "rp_launch_attributes")
-        self.rp_tests_attributes = self.find_option(pytest_config, "rp_tests_attributes")
+        self.rp_launch_attributes = normalize_attributes(self.find_option(pytest_config, "rp_launch_attributes"))
+        self.rp_tests_attributes = normalize_attributes(self.find_option(pytest_config, "rp_tests_attributes"))
         self.rp_launch_description = self.find_option(pytest_config, "rp_launch_description")
         self.rp_log_batch_size = int(self.find_option(pytest_config, "rp_log_batch_size"))
         batch_payload_size_limit = self.find_option(pytest_config, "rp_log_batch_payload_limit")
diff --git a/setup.py b/setup.py
index 7dd91d5..edae772 100644
--- a/setup.py
+++ b/setup.py
@@ -17,7 +17,7 @@
 
 from setuptools import setup
 
-__version__ = "5.6.6"
+__version__ = "5.6.7"
 
 
 def read_file(fname):
diff --git a/tests/integration/test_attributes.py b/tests/integration/test_attributes.py
index a09e58c..cff940c 100644
--- a/tests/integration/test_attributes.py
+++ b/tests/integration/test_attributes.py
@@ -168,3 +168,40 @@ def test_rp_tests_attributes_add(mock_client_init):
     assert len(attributes) == 2
     assert {"key": "scope", "value": "smoke"} in attributes
     assert {"key": "test_key", "value": "test_value"} in attributes
+
+
+@mock.patch(REPORT_PORTAL_SERVICE)
+def test_rp_tests_attributes_string_split_and_deduplicated(mock_client_init, monkeypatch):
+    """Verify string `rp_tests_attributes` are split and deduplicated."""
+    monkeypatch.setenv("RP_TESTS_ATTRIBUTES", " test_key:test_value ; smoke ; test_key:test_value ")
+    variables = {}
+    variables.update(utils.DEFAULT_VARIABLES.items())
+    result = utils.run_pytest_tests(tests=["examples/test_simple.py"], variables=variables)
+    assert int(result) == 0, "Exit code should be 0 (no errors)"
+
+    mock_client = mock_client_init.return_value
+    assert mock_client.start_test_item.call_count > 0, '"start_test_item" called incorrect number of times'
+
+    call_args = mock_client.start_test_item.call_args_list
+    step_call_args = call_args[-1][1]
+    actual_attributes = step_call_args["attributes"]
+
+    assert utils.attributes_to_tuples(actual_attributes) == {("test_key", "test_value"), (None, "smoke")}
+
+
+@mock.patch(REPORT_PORTAL_SERVICE)
+def test_rp_launch_attributes_string_split_and_deduplicated(mock_client_init, monkeypatch):
+    """Verify string `rp_launch_attributes` are split and deduplicated."""
+    monkeypatch.setenv("RP_LAUNCH_ATTRIBUTES", " launch_key:launch_value ; smoke ; launch_key:launch_value ")
+    variables = {}
+    variables.update(utils.DEFAULT_VARIABLES.items())
+    result = utils.run_pytest_tests(tests=["examples/test_simple.py"], variables=variables)
+    assert int(result) == 0, "Exit code should be 0 (no errors)"
+
+    mock_client = mock_client_init.return_value
+    assert mock_client.start_launch.call_count > 0, '"start_launch" called incorrect number of times'
+
+    launch_call_args = mock_client.start_launch.call_args_list
+    launch_attributes = launch_call_args[0][1]["attributes"]
+
+    assert {("launch_key", "launch_value"), (None, "smoke")} <= utils.attributes_to_tuples(launch_attributes)
diff --git a/tests/unit/test_config.py b/tests/unit/test_config.py
index c1c932a..f29c8e2 100644
--- a/tests/unit/test_config.py
+++ b/tests/unit/test_config.py
@@ -79,3 +79,37 @@ def test_env_var_overrides_log_level(monkeypatch, mocked_config):
 def test_env_var_not_set_falls_back_to_config(mocked_config):
     config = AgentConfig(mocked_config)
     assert config.rp_endpoint == "http://docker.local:8080/"
+
+
+@pytest.mark.parametrize(
+    ["option_name", "option_value", "expected_result"],
+    [
+        ("rp_launch_attributes", " smoke ; launch:demo ; smoke ; launch:demo ", ["smoke", "launch:demo"]),
+        ("rp_tests_attributes", " test:key ; smoke ; test:key ", ["test:key", "smoke"]),
+    ],
+)
+def test_string_attributes_are_split_and_deduplicated(mocked_config, option_name, option_value, expected_result):
+    mocked_config.option.rp_launch_attributes = None
+    mocked_config.option.rp_tests_attributes = None
+    mocked_config.getini.side_effect = lambda x: option_value if x == option_name else None
+
+    config = AgentConfig(mocked_config)
+
+    assert getattr(config, option_name) == expected_result
+
+
+@pytest.mark.parametrize(
+    ["option_name", "option_value"],
+    [
+        ("rp_launch_attributes", ["smoke", "smoke"]),
+        ("rp_tests_attributes", ["test:key", "test:key"]),
+    ],
+)
+def test_attributes_not_split_if_not_string(mocked_config, option_name, option_value):
+    mocked_config.option.rp_launch_attributes = None
+    mocked_config.option.rp_tests_attributes = None
+    mocked_config.getini.side_effect = lambda x: option_value if x == option_name else None
+
+    config = AgentConfig(mocked_config)
+
+    assert getattr(config, option_name) == option_value