To better understand the nature of the memory deficit in patients with multiple sclerosis, we designed a study to compare automatic vs effortful memory processes. Forty-one patients with definite multiple sclerosis and 45 demographically matched normal control subjects were administered two tasks designed to assess both automatic (monitoring frequency and modality) and effortful (free and cued-recall) processing. Results indicated that patients with multiple sclerosis, as expected, were significantly impaired on memory measures requiring effort, but performed normally on automatic measures. Performance on the memory indexes did not correlate with self-reported depression. The implications of these findings for delineating the locus of the memory impairment in multiple sclerosis is discussed.