ObjectivesTo examine the association between subjective and objective prospective memory (PM) in people with multiple sclerosis (PwMS). DesignSecondary analysis of a cross-sectional cohort study. SettingCommunity-based comprehensive multiple sclerosis center. ParticipantsPwMS (N=112) who completed a battery that included measures of PM, depression, and fatigue. InterventionsNot applicable. Main Outcome MeasuresObjective PM was measured with the performance-based Memory for Intentions Test (MIST), whereas subjective PM was assessed with the self-report Perceived Deficits Questionnaire-Prospective Memory (PDQ-PM). ResultsPwMS had low scores on the PDDS (median=2) and HADS-D (median=5.29), with 26.8% scoring 1 standard deviation or lower (≤15th percentile) on the MIST. Objective PM was significantly associated with subjective PM in a multivariate model (β=−0.18, P=.036), which accounted for demographics, physical disability, retrospective memory, and depressive and fatigue severity. Physical disability, depression, and fatigue were also significant contributors to subjective PM. Time-based PM performance emerged as the specific component that was associated with subjective PM. ConclusionsThese findings suggest that among PwMS with relatively mild impairment and symptomatology, their objective PM performance was associated with their self-assessments, even when considering retrospective memory and factors that influence their cognitive perceptions. The results expand upon the subjective-objective cognition discrepancy literature in multiple sclerosis and highlights how the PDQ-PM could be used as a complementary measure to help identify difficulties with PM.