The purpose of this study was to explore the interrelationship of social and adaptive skills in adults with bipolar disorder and severe or profound intellectual disability. A bipolar group (N=14), a severe psychopathology group without bipolar disorder (N=14), and a control group with no DSM-IV Axis I diagnosis (N=14) were compared on the "Vineland Adaptive Behavior Scale" (VABS) and the "Matson Evaluation of Social Skills for Individuals with Severe Retardation" (MESSIER). Bipolar patients had significantly more negative verbal social skills than the other two groups on the MESSIER, but no group differences on the VABS were noted. The implications of these data are discussed for a better understanding of bipolar disorder in persons with intellectual disability.