A widely accepted method of job analysis, the critical incident technique, was applied in order to determine dimensions of performance among psychology interns. All training directors of Association of Psychology Internship Centers were contacted regarding participation, and 46 (90%) completed the critical incident interview. The 270 critical incidents were analyzed with a standard procedure for determining behaviorally defined job dimensions. Seven dimensions were identified: clinical skills, commitment to own professional development, crisis and emergency situations, interpersonal relationships, knowledge, professional and ethical behavior, and programming and consultation skills. The results are presented within the context of other definitions of intern performance and of entry-level psychological practice. In addition, suggestions for improving selection and evaluation of psychology interns are presented.