The effect of hook size and seasonality on the artisanal long-line fishery of southern hake (Merluccius australis) in Chile was studied. We analyzed the effect of four hook sizes on the size-at-catch and catch rates of southern hake (Merluccius australis) caught with mixed long-lines between Seno de Reloncavi and Golfo de Ancud (41 degrees 42'S-42 degrees 48'S). Sixty fishing hauls were done in four periods (March, May, July, September); a total of 59,294 hooks were set and 14,358 specimens (26,165 kg) were caught. The analysis showed overlapping retention sizes for each hook size in the months studied, indicating no significant effects in either catch size composition or in catch rates between hooks of different size. Nevertheless, significant differences were observed between periods in the catch rates, fluctuating between 31.75 and 16.17 individuals per 100 hooks from March to September. The above results suggest that it is necessary to analyze alternative fishing gear and management measures for the fishery.