A total of 168 Negro and 296 white Medical Technicians participated in this study. A nine-scale performance rating form was developed and administered. Every technician was rated by at least two supervisors. A test of job knowledge was also given to all subjects. Among the correlations found were: (1) Negro workers received distinctly higher ratings on all nine scales from supervisors of their own ethnic group than from white supervisors, (2) Negro raters tended to give higher ratings in general than white raters when rating the same individuals, but the effect was more marked for Negro subordinates than for whites; (3) different relationships exist between scores on the Job Knowledge Test and the criterion of Job Knowledge ratings, depending upon the interaction of the race of the rater and that of the person being rated. Basically, the measures showed that the race of both the person being rated and the person doing the rating has a noteworthy influence on the evaluation received. (KJ)