Objective: To develop an instrument to assess client-centered counseling behaviors (skills) of student-counselors in a standardized patient (SP) exercise. Methods: Descriptive study of the accuracy and utility of a newly developed counseling evaluation instrument. Study participants included 11 female student-counselors at a Midwestern university--10 Caucasian, 1 African-American--for the simulated counseling sessions, in which the Feedback on Counseling Using Simulation (FOCUS) instrument was applied in 2 SP scenarios (cardiovascular disease and diabetes). FOCUS ratings of student-counselors by 4 SPs during 22 sessions were compared with ratings from a 3-member panel of experts who independently viewed the 22 videotaped sessions. Quantitative analysis of instrument validity included inter-rater reliability by computing generalizability coefficients, Pearson correlations, and Spearman rank-order correlations. Results: FOCUS criteria encompassed relevant dimensions of nutrition counseling based in a client-centered perspective. The critical points of information gathering and counseling behaviors showed internal consistency overall and good inter-rater reliability with the cardiovascular disease scenario. For both scenarios, pooled ratings of 3 experts agreed with ratings carried out by SPs. Conclusions and Implications: Initial findings suggest that the FOCUS instrument with client-centered criteria may enhance evaluation of counseling skills in SP exercises, meriting further study with larger groups. (Contains 2 tables.)