This study was performed with the purpose of determining the main feeding aspects and the reproductive period of Saurida undosquamis from January to December 2010. The samples were obtained by trawl operations conducted in monthly intervals. The result regarding the feeding reveals that the most important feeding group is the teleost. The IRI values (20621,06) for the teleost are much higher than those determined for crustaceans and cephalopods (31,66 and 0,02, respectively). The relative importance of the clupeiforms among the teleosts was the highest (Clupeidae: 1890.13; Engraulidae: 910.06). In addition, while the sex and length were not significant predictors of the feeding groups, their variation, depending upon the month, was important. In general, the pelagic and native species were dominant in feeding preference. However, feeding with the demersal and indopacific species was more common in October and November. Moreover, the prey length increased with the predator length. The reproductive activities of this species increased during the warm months, and there was a negative correlation between the spawning activities and the feeding intensity.