This study investigated the relationships between variables affecting the degree to which cooperative learning (CL) was implemented by English as a Second Language (ESL) and bilingual teachers. A total of 227 ESL and bilingual public school teachers (K-12) of Spanish speaking language minority students responded to a mailed survey questionnaire that was constructed to examine: (1) teacher beliefs about the acquisition of knowledge, teacher role, and second language instruction; (2) teacher attitudes about various aspects of CL; and (3) teacher perceptions of constraints and opportunities in their school environment. The study found that ESL and bilingual teachers with high interpretive beliefs tended to implement CL more frequently than teachers with low interpretive beliefs. The teachers that most frequently implemented CL were those who perceived the teacher's role to be of a more inclusive nature. (Contains 24 references.) (MDM)