Age, growth and population structure of the jumbo flying squid, Dosidicus gigas, from the jig fishery in Peruvian waters in 1992 were determined by reading daily increments in ground and polished sections of statoliths. The squid ranged in size from 192 to 965 mm dorsal mantle length (ML) and no squid were older than 1 year. Two size groups were present in the exploited population; one group of small individuals <490 mm ML and another group of larger individuals >520 mm ML, with maximum ages of 220 and 354 days, respectively. The date of hatching estimated by back-calculation, revealed the presence of two cohorts of small squid; one hatched in autumn/winter and recruited to the fishery in spring/summer and the other hatched in spring/summer and recruited to the fishery in autumn/winter. © 2001 Published by Elsevier Science B.V.