This study examined the frequency of social comparisons in a work setting, and the feelings that these comparisons evoked. These processes were related to individual differences in social comparison orientation, and to the perception of a cooperative social climate at work. The participants were 216 physicians from various health centers in the Community of Valencia in Spain. In general, upward comparisons occurred more often, and elicited more positive and less negative affect than downward comparisons. Those high in social comparison orientation reported relatively more upward as well as downward comparisons, more positive affect after downward comparisons, and more negative affect after upward comparisons. Conversely, those who perceived the social climate at work as cooperative reported relatively more downward comparisons, more negative affect after downward comparison, and more positive affect after upward comparison. Among the 87 participants who participated in the longitudinal part of the study, perceived cooperative climate and social comparison orientation were more stable over a period of one year than the frequency of upward and downward comparison and the affective consequences of upward and downward comparison. It is concluded that individuals interpret social comparisons at work in a positive way when they perceive the social climate as cooperative, and in a negative way when they are high in social comparison orientation.