Thirty patients with chronic pure mitral regurgitation who underwent mitral valve replacement during 1981 to 1986 were evaluated for pre- and one year postoperative left ventricular function using two dimensional echogram. Indicators in their evaluation were DdI, DsI, MassI and systolic and diastolic R/Th. Postoperatively, patients (n = 7) were placed in a group of abnormal responses if even one of these indicators of left ventricular function became worse than preoperative performance, patients in this group were symptomatic and two subsequently died. The postoperative FS and mVcf data fort this group were significantly lower than the patients with normal response group (n = 23). These two groups could not be differentiated by preoperative assessments of either DdI, MassI, systolic/diastolic T/Th or normalized systolic/diastolic peak velocity. However, a combination of normalized systolic peak velocity lower than 1.70 and diastolic peak velocity lower than 2.20 of left ventricular wall motion proved to be good predictors of postoperative results.