Negative affectivity (NA) has been defined as a stable and pervasive individual difference characterized by a disposition to experience aversive emotional states (D. Watson and L. A. Clark, 1984). A brief self-report scale was developed to assess NA. The initial 28-item scale (which included seven items each representing nervousness/calmness, self-dissatisfaction/self-satisfaction, pessimism/optimism, and cynical/trusting attitudes about other people) was administered to two separate samples of undergraduates (N=381 and N=323). Principal components analysis produced a 21-item scale, which did not include any of the cynicism/trust items. Eighty-five subjects completed the revised scale twice, with a 6-week interval. The test/retest correlation for these subjects was 0.88. The congruent validity and discriminant validity of the scale were investigated by correlating the scale with measures of constructs hypothesized to be related or not related to NA, based on prior research. Undergraduate psychology students (N=111) participated in studies indicating that the NA scale significantly correlated with the Taylor Manifest Anxiety Scale, the Eysenck Neuroticism Scale, the Rosenberg Self-Esteem Scales, and the Eysenck Extraversion Scale. As expected, no relation was found between the NA scale and the Remote Associates Test. The NA scale did correlate with the Shipley Vocabulary Subscale, although no explanation is offered for this correlation. One table presents item-scale correlations for the two original samples. (SLD)