Physical therapist education consists of two distinct elements: the didactic preparation and the clinical education experiences. Clinical instructors at affiliated clinics supervise physical therapist students during clinical education. A clinical instructor can receive additional training through two commonly offered programs: Clinical Performance Instrument (CPI) training, which involves 1 hour of instruction, and Clinical Instructor Education and Credentialing Program (CIECP), which includes 15 contact hours of instruction and assessment. The purpose of this study was to determine if completion of either or both of these training programs affected the rating of the CPI by a clinical instructor. Thirty-four licensed physical therapists participated in the study. They were current clinical instructors or physical therapists who were interested in becoming clinical instructors. The subjects were shown a videotape of a simulated student interacting with a simulated client. The subjects were asked to rate the student's performance using the first five criteria of the CPI. The first five criteria were selected for the study because of their designation as determinants for a successful clinical education experience. Background and demographic data were gathered in addition to the CPI ratings. Four groups of clinical instructors were determined from their previous training, then differences in CPI ratings were analyzed. The groups were CIECP and CPI training, CIECP training only, CPI training only, and no training. A multivariate analysis of variance showed statistical significance between training groups but no statistical significance based on previous use of the CPI. Post hoc tests identified the differences as occurring between the group with CIECP and CPI training compared with the groups with only CPI training or no training when rating the first criterion for safety. Rating the second criterion of responsible behavior was different between the CIECP-only group and the CPI only group. This study indicated that completion of CIECP and CPI training affected rating of the first criterion of the CPI compared with clinical instructors who completed the CPI only. Completion of the CIECP only affected the rating of the second CPI criterion compared with CPI-only training. Previous use of the instrument was not significant in this study. Assessment of student performance in the clinical setting is a complex task and further analysis of the training and use of the CPI is needed.