The current study investigated the effects of rater motivations on performance appraisals (PA). Despite rater motivations being important to PAs, there is no established and validated scale to measure rater motives. Within this study, a scale was developed to measure five rater motives. This scale, labeled the Performance Appraisal Motivation Scale (PAMS), was then examined for internal structure and validated using data from current managers. PAMS exhibited acceptable internal structure and displayed an expected pattern of relationships with individual difference variables, situational variables, other rater motives, and rating outcomes. Overall, results provide evidence in support of PAMS' construct validity. The findings also help establish empirical linkages between rater motivations and important variables within the nomological network of rater motivation.