This study examined the relationship of compliance with homework assignments and posttreatment anxiety in patients who received cognitive-behavioral group therapy (CBGT) for social phobia. Greater homework compliance measured in the first and latter periods of CBGT was associated with lower levels of social interactional anxiety after treatment. Surprisingly, homework compliance during the middle sessions of CBGT was positively related to posttreatment fears of scrutiny and criticism. Perceptions of control in social phobia and their potential effect on homework compliance and the homework compliance/treatment outcome relationship were also examined using the Levenson (Journal of Consulting and Clinical Psychology, 41, 397-404, 1973) Locus of Control Scale. Social phobics were less likely to believe in their own control over events than a comparison sample of community subjects but attributed greater control over events to other powerful persons. Among patients, higher Internality and lower Powerful Others subscale scores were associated with higher levels of pretreatment anxiety. However, neither subscale was significantly related to measures of homework compliance. Furthermore, when included in multiple regression analyses, neither subscale or its interaction with homework compliance added to the prediction of posttreatment anxiety. Limitations of this study and future research to improve assessment of homework compliance and perceptions of control among social phobic patients are discussed.