The purpose of this study was to evaluate median nerve short latency somatosensory evoked potentials (SEP) as prognostic indicators of functional outcome after right cerebral infarction. Twenty-six patients with right cerebral infarction were admitted to a rehabilitation unit and were classified into three groups based on the evoked potentials measured on admission. The SEP classification and nine other variables reported to predict recovery after stroke were evaluated for prediction of the final outcome measure, the Barthel Scale, using stepwise multiple regression analysis. Patients with normal SEP achieved a mean Barthel score of 95 +/- 3.9 SD, while patients with an amplitude asymmetry on SEP showed a mean Barthel score of 77.5 +/- 17.5 SD. The group with absence of cortical potentials had a mean Barthel score of 59.5 +/- 21.3 SD. Six predictors (Barthel admission score, SEP, electroencephalogram, Brunnstrom staging of the arm at the time of admission, joint position sense, and hemihypesthesia) were highly correlated with the Barthel outcome score (p less than 0.05 for all). The linear regression equation with three predictors (Barthel admission score, SEP, and homonymous hemianopsia) provided the best prediction of Barthel outcome score (p = 0.005). These data indicate that the Barthel admission score is the best predictor of functional level after stroke rehabilitation. Knowledge of the median SEP and homonymous hemianopsia improve this prediction.