Correlations were evaluated between personality factors, as measured by the EPI, and treatment outcome in obsessional-compulsive patients. The results suggest that extraverts have a slightly better outcome than introverts when treatment is carried out with a time-limit. After treatment to criterion extraversion failed to correlate with outcome. The Neuroticism scale (N) correlated with assessment variables before treatment as well as after. There was, however, an indication that high N scores were predictive of elevated anxiety ratings after treatment. None of the results applied to the sub-group taking clomipramine at the time of assessment.