This article reports the results from a four-year investigation of the relationships among four measures of social cognitive and communication abilities—cognitive differentiation, self-monitoring, perspective-taking, and persuasive ability—and the relationships of these measures to job level and upward mobility in a large East Coast insurance company. The data revealed significant relationships among all combinations of the communication-related abilities. Each was significantly related to job level, and three of the four were significantly related to upward mobility. Stepwise multiple-regression analyses revealed that, of the four communication-related abilities, cognitive differentiation accounted for the most variance in predicting job level and upward mobility. The findings suggest that communication abilities are important to the success of individuals in organizations. Persons with more developed abilities tended to be found at higher levels in the organizational hierarchy and tended lobe promoted more often than persons with less developed abilities.