Coronary artery bypass graft (CABG) and valve replacement (VR) surgical patients underwent neuropsychological assessment 1-2 days prior to surgery; 7-10 days postsurgery; and 1 month following hospital discharge. A group of matched healthy controls was tested at identical intervals. Cerebral microemboli in both middle cerebral arteries were quantified during surgery using Doppler sonography. Neuropsychological testing results revealed that the CABG and VR groups did not differ from one another at any assessment point. However, surgical patients performed more poorly than healthy controls across all assessments. Surgical patients, as a group, demonstrated a mild decline in attentional functioning and learning efficiency at the 7-10 day follow-up, but these difficulties essentially returned to baseline by the 1-month follow-up. Intraoperative microemboli counts were not significantly associated with postsurgical neuropsychological functioning in either the CABG or VR group.