This study presents the reproductive biology of the swordfish caught off the Chilean coast. Biological samples were taken in the economic exclusive zone and oceanic areas adjacent to Easter Island, Salas y Gomez Island, and San Felix and San Ambrosio islands between February 2001 and January 2002 and subjected to histological analysis. The monthly records of reproductively active females, the frequency of ovarian stages, and the gonadosomatic index show that spawning activity is greatest in austral summer, during January and February. An analysis of the oocyte frequency distributions revealed a separation of the most advanced mode around 600 mu m if taking partial fecundity to be oocytes larger than 600 mu m and if the fecundity varies between 0.5 and 31 million oocytes for females with 217 and 303 cm of lower jaw to fork length, respectively. The results indicate that the swordfish could be synchronous by group because, amongst their other characteristics, some specimens show a discontinuity between mature and immature oocytes.