Gender is recognized as a factor that may affect the accuracy of performance appraisals. Gender effects can be considered from several aspects: gender of the raters, gender of ratees, and raters' gender differences in their self-ratings. In recent years, the self-rating has attracted considerable attentions. Results of self-ratings can serve as criteria to validate other assessment procedures, however, they are typically more lenient (i.e. higher) than ratings from other parties. Some studies have found evidence of possible subtle gender bias. Gender effects may highly occur in sex segregated occupations. Researches showed peer ratings exhibit acceptable reliabilities and are more accurate. In this paper we conduct a study on self- and peer rating pairs to clarify gender effects on performance appraisals. We investigated gender effects on self and peer ratings in sex segregated occupations. 263 self- and peer rating dyads participated the study. Results showed that self-ratings were lower than their peers' ratings. This is inconsistent with most literature's results, where self-ratings were considered to be more lenient. Also, the gender seems do not affect the relationship between self and peer ratings. This also indicates an inconsistency with stereotypes of the sex segregated occupation schema implied in literature. Implications, especially from cultural relativity explanations, were discussed. Limitations and future researches were discussed as well.