Loligo sanpaulensis the most abundant coastal squid in southern Brazil. The reproduction of the species was studied from 2,340 specimens obtained in eight groundfish surveys from 198 1 to 1987 along the coast of southern Brazil (28"35' S to 34"40' S), at depths from 10 to 587 m. On the shelf,' ripe specimens and mated females were found in all seasons, being less frequent in autumn. Most squids caught on the slope during all seasons were immature. The high frequency of fully mature females, and the occurrence of spent males, egg masses and loliginid paralarvae suggested that the species spawns off Southern Braz il. Mature individuals were mostly smaller than 80 mm mantle length (ML) in summer and autumn. In winter and spring, two spawning groups, with 50 - 80 mm ML and larger than 100 mm ML, were detected at depths under and over 40 m respectively. Off southern Brazil , the species has a long spawning period, with peaks in summer and winter/spring. The squid migrates across and along the shelf, taking advantage of the Brazil and Malvinas currents system to reach suitable spawning and feeding grounds. It is hypothesized that summer spawners may find adequate feeding grounds in winter in the outer shelf while winter spawners may recruit in part to the southern range of the species in northern Argentina in spring, eventually returning northward to reproduce