Few treatment outcome studies of Obsessive Compulsive Disorder (OCD) have employed Behavioral Avoidance Tests (BATs) to assess changes in symptomatology, probably because of the difficulty of constructing such tests for a disorder which has widely varying symptoms. The few studies that have examined the psychometric properties of BATs for OCD have found mixed evidence for validity but good treatment sensitivity. The present study presents psychometric findings for a multi-step/multi-task BAT that assessed percentage of steps completed, subjective anxiety, global avoidance, and rituals. This measure was used with 50 clients diagnosed with OCD whose symptoms varied widely. The BAT demonstrated good convergent and divergent validity, as well as treatment sensitivity according to effect size calculations. A composite score combining steps, anxiety level, avoidance and rituals also performed well in psychometric tests. Strategies to reduce the complexity of scoring are presented, along with examples of several BAT tasks to enable researchers to employ this behavioral measure.