We report for the first time a study of postlarval and juvenile penaeid shrimps of the Penaidae family for the Gulf of Montijo, Panamanian Pacific. The scope of this work focused on the analysis of relative abundance and sizes of postlarvae of Litopenaeus stylirostris, Litopenaeus occidentalis. Litopenaeus vannamei, and Farfantepenaeus californiensis in breeding areas, taking into account the lunar phases (new moon and full moon) and physicochemical parameters (salinity, temperature and dissolved oxygen) for a period of 12 months (dry and wet seasons). By relating the 4 species of penaeid shrimp with the physicochemical variables, there were no correlations with either season. Abundance peaks were observed specifically for the species L. stylirostris and L. occidentalis in the last months of the rainy season and the beginning of the dry season. Similarly, during the new moon, we found the most abundant peaks for these two species. This recruitment was evident in species with sizes between 5 mm, and 10 mm and 10 mm and 15 mm, which is attributed to the entrance of postlarvae to the estuaries or intertidal zone as part of the renewal of the resource and preferences for areas near the coast.