diff --git a/CHANGELOG.md b/CHANGELOG.md
index cc1d1cfdae105..50bd9fcaaa783 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -98,6 +98,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Fixed failure when `DataLoader(batch_size=None)` is passed ([#10345](https://github.com/PyTorchLightning/pytorch-lightning/issues/10345))
 
 
+- Fixed issue with pickling `CSVLogger` after a call to `CSVLogger.save` ([#10388](https://github.com/PyTorchLightning/pytorch-lightning/pull/10388))
+
 -
 
 
diff --git a/pytorch_lightning/loggers/csv_logs.py b/pytorch_lightning/loggers/csv_logs.py
index 77adfe551f72d..454a17905c529 100644
--- a/pytorch_lightning/loggers/csv_logs.py
+++ b/pytorch_lightning/loggers/csv_logs.py
@@ -95,9 +95,9 @@ def save(self) -> None:
         metrics_keys = list(last_m.keys())
 
         with open(self.metrics_file_path, "w", newline="") as f:
-            self.writer = csv.DictWriter(f, fieldnames=metrics_keys)
-            self.writer.writeheader()
-            self.writer.writerows(self.metrics)
+            writer = csv.DictWriter(f, fieldnames=metrics_keys)
+            writer.writeheader()
+            writer.writerows(self.metrics)
 
 
 class CSVLogger(LightningLoggerBase):
diff --git a/tests/loggers/test_all.py b/tests/loggers/test_all.py
index 67838e219fcfb..271ffce811fe5 100644
--- a/tests/loggers/test_all.py
+++ b/tests/loggers/test_all.py
@@ -263,6 +263,10 @@ def _test_loggers_pickle(tmpdir, monkeypatch, logger_class):
     # the logger needs to remove it from the state before pickle
     _ = logger.experiment
 
+    # logger also has to avoid adding un-picklable attributes to self in .save
+    logger.log_metrics({"a": 1})
+    logger.save()
+
     # test pickling loggers
     pickle.dumps(logger)