A classroom's social environment and student dispositions towards social interaction together exert a substantial influence on academic outcomes. The strength of this effect is highlighted by research showing the positive effect of cooperative learning on student achievement, but can also be seen in the contribution that student social dispositions, specifically one's disposition toward helping others (i.e. prosocial), has on individual achievement. The current study sought to assess the psychometric properties of the original Cooperative Classroom Environment Measure (CCEM) and refine the measure to increase its validity for use in the classroom. The CCEM was developed to provide information to educators about factors in the classroom environment contributing to student prosociality. The original form was answered by 431 undergraduate students enrolled in an introductory life science class. Following data collection, both exploratory factor analysis (EFA) and Rasch analysis were used to remove problematic items and generate a refined form. The psychometric properties of this refined form were examined using Rasch and confirmatory factor analysis, and supported the presence of six (out of eight originally hypothesized) subscale constructs analogous to those influencing prosociality in other contexts. Additional evidence showed the presence of a single prominent underlying latent factor (termed Prosocial) that could account for significant variance in all subscale constructs. These findings provided preliminary evidence for the use of both the CCEM subscales and whole survey measures for investigations into optimizing classroom social environments for prosocial action.