Between September 2006 and June 2007 the composition and abundance of polychaetes associated with intertidal red algae was studied, in 7 stations along the coast of Cordoba, Colombian Caribbean. To collect the specimens a quadrant of 625 cm(2) with 5 replicates randomly arrange at each sampling point was used. All intertidal red algae fronds examined contained polychaetes with a record of 288 individuals belonging to 19 species of 7 families. The most abundant species was Platynereis dumerilii (Nereididae) with 188 individuals, followed by Pseudonereis gallapagensis (Nereididae) with 23 individuals and Syllis corallicola (Syllidae) with 12 individuals. Also the sedentary polychaetes, Hydroides sanctaecrusis (Serpulidae) with 4 individuals and Pista palmata (Terebellidae) with 5 individuals were collected. The highest abundance of polychaetes abundance was recorded in December (T2) and March (T3) with 79 and 103 individuals respectively, and the lowest in September (T1) and June (T4) with 47 and 59 individuals. According to the ANOSIM test there were no significant differences among groups (R = 0.09, P = 0.52). This is because the polychaete P. dumerilii had the highest similarity contribution (> 77%) in each group, indicating which was the most important in terms of abundance in all sampling months. Finally, the species collected in the algal fronds are characteristic species of soft bottom and rocky substrates, suggesting a non-specific adaptation of these species to substrates algal.