This paper reviews literature of psychometric properties of self-appraisals of work performance. It summarizes evidence of leniency, variability, halo, bias, and construct validity. Comparisons with appraisals by supervisors, peers, and subordinates suggest that self-appraisals tend to show more leniency, less variability, and less discriminant validity. Different factor structures have been found among self, supervisor and peer-ratings. On the other hand, self-appraisals showed less halo. Self-appraisals were significantly correlated with other sources in some studies and failed to correlate in many others. Existing data do not allow any conclusion whether the quality of self-appraisals is a function of scale format, amount or rater training, type of judgment, or purpose of appraisal. The effects of the observed psychometric qualities of self-appraisals on various applications are discussed. Problems may exist when they are used for administrative decision making, diagnosis of training needs, applied criterion measurement, measurement of constructs in basic research, or for selection purposes.