Collaborative teaching, a significant concept in the field of English language teaching, involves teachers in sharing expertise, decision-making, lesson delivery, and assessment. It is a common practice for instructors in many schools and universities where English is taught as a foreign/second language (EFL/ESL) in intensive programs or departments to be involved in collaboration in many ways ranging from co-planning to coconstructing and co-teaching their language classes. The present study concentrated on collaborative practices of English language instructors planning the EFL program together at a private university in Istanbul, Turkey. It aimed to elaborate on the ways they were engaged in collaboration in language teaching, their beliefs on it, and which conditions they perceived as necessary to sustain successful collaboration. The results gained from written pre-interview protocols, focus-group and individual interviews shed light on the characteristics of collaborative teaching practice for the participants, the factors that might foster or hinder successful collaboration in teaching English, and the ways to improve collaborative teaching for all parties involved in such an experience of teaching.