SummaryThere is a very large research base in Applied Psychology on the importance of aective reactions on organizational functioning. Likewise, performance appraisal has been a heavily researched area within the ®eld. The present ®eld studies attempt to bridge our understanding of these two areas by studying the relationship between performance appraisal process variables and employee aective reactions. In particular, the current studies examine the eects of a relatively new performance appraisal variable, Perceived System Knowledge (Williams and Levy, 1992), on appraisal reactions and job attitudes. In both studies, there was a strong relationship between employees' levels of perceived system knowledge and their appraisal reactions and job attitudes. In Study 1, when controlling for performance rating, PSK was positively related to appraisal reactions, job satisfaction, and organizational commitment. The ®ndings from Study 1 were replicated in the second study which employed a longitudinal design. In addition, Study 2 found a relationship between PSK and fairness perceptions. Implications for these results and suggestions for approaching performance appraisal from an organizational perspective are proposed.