Nursing employees at four nursing homes participated in the development of Behavioral Anchored Rating Scales (BARS) to measure the job performance of individual nurses and aides. The reliability of the BARS performance measures was examined by having the immediate supervisors evaluate the job performance of nurses and aides in ten nursing homes.The BARS evaluations had significant convergent reliability between two independent evaluations of the same employees. There were no significant differences in the employees' performance ratings provided by two independent raters. Moreover, both raters tended to agree on the direction and magnitude of the changes in job performance ratings that were recorded over a six-month interval. The BARS evaluations, however, indicated a leniency bias because the performance ratings tended to cluster in the upper half of the scale ranges. There was also a “halo” effect in the evaluations, resulting in little discriminant reliability between the employees' performance ratings on different job dimensions.