Interpersonal affect has been found, in prior laboratory research, to be related to ratings of job performance. Such findings have been taken to mean that affect creates bias in ratings. The present study was conducted to determine if this relationship would hold up in a field setting. The present study was also designed to examine how structured diary-keeping, and the nature of the appraisal instrument, might be related to affect-appraisal relationships. The results for 85 raters, and 404 ratees, suggested that affect was significantly related to all ratings, but more strongly related to trait-like ratings than task/outcome-like ratings, and that having raters keep performance diaries actually increased the strength of the relationship between affect and ratings. We concluded that affect may not be a biasing influence on ratings, but may be a result of better subordinate performance. Results from an analysis of the diary content supported this conclusion. Implications for the role of affect on ratings and the nature of the relationship between past performance and interpersonal affect in field settings are discussed.