A measure assessing client views of the community supports available to them was developed and tested with entrants to outpatient drug free treatment. Items for a Community Assessment Inventory (CAI) fell into four areas of potential social support for treatment entry and engagement: (1) partner and/or family with whom living; (2) family living outside the home; (3) friends; and (4) the community itself. Based on 241 study participants, it was found that internal consistency alphas for the four scales ranged between .79 and .88. Both total CAI score and individual scales assessing support from friends and from partner/spouse were found capable of predicting treatment readiness as assessed using the TCU Motivation Scale. Evidence of construct validity was suggested by differences in CAI total score between participants reporting and not reporting involvement in discussions with others regarding crime and regarding drugs. Findings are also provided regarding leisure time activities and social relations of treatment entrants.