Neuropsychological research indicates that the left hemisphere plays a dominant role in verbal production and processing, while the right hemisphere plays a dominant role in nonverbal production and processing. This study sought to examine the effects of such differential hemispheric specialization on personality and social competency. Ten left hemisphere damaged (LHD) stroke patients, 11 right hemisphere damaged (RHD) stroke patients, and 7 neurologically normal (NHD) patients were videotaped while engaging in social interaction with their spouse and an interviewer. Segments of the interactions were independently coded by two observers. Patients and spouses were rated with respect to their level of social competency and the extent to which they were characterized by 10 personality adjectives (e.g., outgoing, warm). Ratings for the personality items were summed to create an aggregate score. Analysis of these scores revealed both LHD and RHD patients to have lower (i.e., more negative) mean scores than NHD patients, suggesting that stroke patients as a whole were seen as socially impaired. Analysis of the socially competent item revealed particular LHD deficits; LHD patients were seen as less socially competent than both RHD and NHD patients. Spouses of LHD, RHD, and NHD patients, in contrast, did not differ in observer-rated social behavior. (JINS, 1998, 4, 447–455.)