This study examined teamwork (Shared Vision-SV, communication and collaboration) and lecturer Research Output (RO) in Colleges of Education (CoE) in Southwestern Nigeria. Survey design of the correlational type was adopted for the study.Three states (Oyo, Ogun and Lagos) were purposively selected based on the presence of federal and state CoE. Six CoE (three each of federal and state) were randomly selected. They are the Federal College of Education (Special), Oyo; Federal College of Education (Technical), Akoka; Emmanuel Alayande College of Education, Oyo; Michael Otedola College of Primary Education, Noforija, Epe; Tai Solarin College of Education, Omu-Ijebu; and Federal College of Education, Osiele, Abeokuta. Two self-developed instruments: Teamwork Questionnaire and Publication Checklist were used to collect data. Descriptive statistics was used to answer research questions while multiple regression analysis was employed to test hypothesis. The level of lecturer RO was low ( =1.91), while the level of teamwork among lecturers was high ( =3.24) in CoE in SouthwesternNigeria.Significant contribution was found between collaboration andlecturer RO (β=0.20,p<0.05). However, there is no significant contribution of communication (β=0.00, p>0.05) and SV (β=0.05,p>0.05) to leacturer RO. College management should sustained and maintained teamwork for enhanced lecturer research output in Colleges of Education in Southwestern Nigeria.