ABSTRACT In the period March 2009-February 2010 the fish bycatch of the artisanal shrimp fishery operating off the beach of Isla del Rosario (Gulf of Salamanca, Colombian Caribbean) was evaluated and length-frequency data analysis were done for five of the main ichthyic species. For this purpose, data registered in the project “Pesca artesanal del Magdalena”, processed in the Fisheries Information System of Invemar (SIPEIN) to obtain fishery variables, on a monthly basis, was used. Between shrimp and fish fauna 38,265 kg were registered. The ichthyic bycatch fauna was composed of 59 fish species, distributed in 23 families, being Engraulidae, Sciaenidae, and Mugilidae the most representative. Regarding the engraulid Cetengraulis edentulus biomass, it was the most important species. Ichthyic bycatch to shrimp relationship was 1.2:1.0 with shrimp beach seine. During the assessed year, the highest mean Landing Per Unit Effort (LPUE) was present in the dry season, but November (rainy season) was the month with the highest shrimp LPUE. The indicators, Lc (mean length) and spawning/juvenile proportion, evidence growth overfishing for the species Bairdiella ronchus, Cathorops mapale, Mugil incilis and Trichiurus lepturus. The state of this fishery and the impact it generates on the ecosystem is discussed. Measures for its proper management are recommended.