Professional development of language teachers is one major measure to ensure that teachers remain updated and avoid the risk or leaving the profession. Not all teachers, however, attend professional development (PD) workshops or engage in such activities for the sake of developing professionally. Some teachers attend PD courses on a routine basis with little knowledge of what competencies they are expected to gain as a result, and simply because taking part in such programmes is an institutional requirement. To explore the type of PD activities English teachers in Iran participate in and also to understand the motivations behind their participation, the researchers interviewed 24 English teachers (with the age range of 24–50) working at private language institutes and public high schools. The study found that public school teachers were engaged in very few PD activities, and the type of PD activities private teachers followed ranged from consulting online courses to watching educational videos to reading ELT textbooks. The motivations for taking part in PD activities ranged from ‘having no motivation’ to ‘promoting my English’ to ‘being able to teach at university’. Further results and implications for teacher education in Iran and beyond are discussed in the paper.