We recently reported that visuospatial working memory capacity predicts the rate of explicit motor sequence learning (Bo and Seidler in J Neurophysiol 101:3116-3125, 2009). In the current study, we evaluated relationships between visuospatial and verbal working memory and implicit performance change in the serial reaction time (SRT) task. Participants performed two computerized working memory tasks adapted from change detection working memory assessments, an implicit SRT task, and several neuropsychological tests. We observed significant correlations between visuospatial working memory (VSWM) and verbal working memory (VWM) performance. VSWM, VWM, and card rotation task were each significantly correlated with the rate of reaction time improvement in the SRT task. Multiple linear regression analysis revealed that VSWM explained a significant portion of the variance in rate of SRT performance change (exponential fit to the performance curve) across individual participants, and the addition of VWM did not significantly improve the model. These findings suggest that VSWM plays a role in the implicit performance improvement of second-order conditional sequences.