The present study “Professional Development Through an English Teachers Study Group” is a descriptive and interpretative case study where four (4) English teachers were involved in a professional development process. The study was held in an English language institute in Pereira, Colombia. The aim of the study was to obtain information of the processes undertaken by the teacher-participants while they strove to improve their job related knowledge through a study group. Nevertheless, the space provided through the study group served to laid and treat diverse teaching concerns by being exposed to different means of knowledge that helped ameliorate these issues. The data were gathered through the use of a survey, reflective logs, audio transcriptions of the sessions, and a final interview. The collected data was analyzed in order to obtain the findings that gave answer to the following research questions: What is the role of reflection presented in an English teachers study group? - What teaching necessities are presented and addressed in an English Teachers Study Group? - What can an English Teachers Study Group inform us about its participant’s collaborative learning work?