This article presents an overall exploratory comparison of the English teacher training courses (TTCs) held in Iranian private language institutes and Certificate in Teaching English to Adults (CELTA). Data were gathered through Iranian institutes’ websites; interviews with Iranian English teachers, English teachers holding CELTA certificate, and teacher trainers; as well as questionnaires filled out by institutes’ supervisors and CELTA holders. Content analysis and document analysis were conducted to reveal the similarities and differences between CELTA and Iranian TTCs. Results showed that Iranian TTCs were quite different from CELTA, especially at implementation and evaluation stages. The findings revealed that Iranian TTCs neglected the trainees’ needs, limited the teachers to a series of practical steps in teaching, did not provide enough opportunities for teaching practice, and evaluated the trainees’ performances subjectively. However, they enjoyed systematic planning, contained practical techniques for teaching the language components and skills, and were based on institutes’ needs. Iranian teacher trainers are advised to involve the trainees more in the implementation of the course through doing assignments, to provide the trainees with video recordings of the experienced teachers’ classes for observation, and develop an objective criterion for assessing the trainees’ teaching performances.