diff --git a/arrow-array/src/record_batch.rs b/arrow-array/src/record_batch.rs
index c56b1fd308c..78108d441b0 100644
--- a/arrow-array/src/record_batch.rs
+++ b/arrow-array/src/record_batch.rs
@@ -469,6 +469,11 @@ impl RecordBatch {
     }
 
     /// Returns the total number of bytes of memory occupied physically by this batch.
+    ///
+    /// Note that this does not always correspond to the exact memory usage of a
+    /// `RecordBatch` (might overestimate), since multiple columns can share the same
+    /// buffers or slices thereof, the memory used by the shared buffers might be
+    /// counted multiple times.
     pub fn get_array_memory_size(&self) -> usize {
         self.columns()
             .iter()