Studies of Emotional Intelligence have been limited to the individual level of analysis, yet the literature shows that group dynamics play a crucial role in group performance and effectiveness. In this study, an assessment instrument to measure group Emotional Intelligence as conceptualized by Druskat and Wolff (2000) was developed. The instrument and four subscales of Hemphill's (1956) Group Dimensions Description Questionnaire were administered to a total of 167 people from groups in business organizations in the Eastern and Midwestern United States. Coefficient Alpha was calculated for each of the 13 subscales on the Group El instrument to assess reliability and scores on the four subscales of the Group Dimensions Description Questionnaire (intimacy, control, viscidity and hedonic tone) were compared with the Group EI subscales to determine convergent and divergent validity. A confirmatory factor analysis was conducted on the data in an effort to confirm the 6 dimensions proposed by Druskat and Wolff (2000) as underlying the 13 subscales. Eight of the 13 original subscales were found to be reliable. Building relationships and ambassadorial orientation, and team self-evaluation and seeking feedback were combined to form two additional subscales with Coefficient Alphas over .8, for a total of 10 reliable subscales. Convergent and divergent validity emerged as expected. Five of the six dimensions proposed in Druskat & Wolff's (2000) theory as underlying the subscales were confirmed: group regulation of members, group self-awareness, group self-regulation, group social awareness, and group social skills. Suggestions for further study and application are made.