The feeding habits of the king soldier bream Argyrops spinifer (Forsskål, 1775), were examined in the northern part of the Persian Gulf (coastal waters of Bushehr, Iran). The stomach contents of 622 specimens, 13.5–64.2 cm in total length, collected by a trawl boat from June 2010 to May 2011, were analysed to assess the influence of size, season and sex on their diet composition. Amongst the examined stomachs, 57 were empty (vacuity index = 9.2%), which varied significantly (P < 0.05) throughout the year. According to the results, this species is a generalist carnivorous feeder with a diet consisting of 52 different prey items belonging to nine main categories. Bivalvia, Gastropoda, Malacostraca, Crustacea and Teleostei were the most important prey items. Fish size and gender showed no significant effects on diet composition. Moreover, in the main food catagories no seasonal variations were detected.