The reliability and validity of the Inventory of Socially Supportive Behaviors (ISSB), a measure designed to tap behaviors pertaining to the provision of social support, were studied. Data were analyzed on a pre-test sample of 100 adults from a community-based, epidemiologic study of 1,008 black adults in Virginia. Findings are presented on the internal consistency of the ISSB, including its dimensionality and the relation of the scale to the other aspects of social support such as structural social support network characteristics. Results show that the ISSB has reliability for use with community-based minority groups, is a reasonable measure of social support, and has very good internal consistency. However, its validity was not supported. Cognitive/informational support and appraisal/emotional support were the most robust dimensions of the ISSB. For black adults, support that results from the self-affirming and self-validating messages inherent in these types of supportive interaction seem to be important. The findings are compared to those of previous researchers such as M. Barrera et al (1983) and J. P. Stokes and D. G. Wilson (1984). Component One from the principle components analysis and components of the ISSB from the varimax rotation are listed. (TJH)