Taxonomic composition of the meroplankton and the pelagic polychaetes of the Cilician basin shelf waters was investigated for the first time. Analysis of monthly net samples shows that the meroplankton and the pelagic polychaetes of the region are represented under 5 phyla, 10 classes, and 34 families. Pelagic nectochaete larvae of the family Spionidae (Polychaeta) and zoeas of family Grapsidae (Decapoda) were the dominating groups throughout the year. Typical stenohaline taxa formed by classes of Enteropneusta, Ophiuroidea, Asteroidea, Echinoidea, and Holothuroidea were also observed. The predominance of the decapod larvae was a distinguishing feature of the winter period. Diversity was highest during the spring (Margalef's Index d = 4.3, 5.4, and 5.6 for March, April, and May, respectively) and lowest during August (d = 1.9) and November (d = 2.3). Results of multivariate analysis (Multi-Dimensional Scaling) revealed a distinct summer population that varied greatly from the rest of the periods. Temperature rather than salinity was found to be more effective in controlling the abundance and diversity in the region.