Variations in zooplankton abundance and composition in the inshore waters of the Gulf of Oman were investigated from July 2005 to February 2006 in relation to environmental variables. Zooplankton samples were collected from two stations, inshore Bandar Khayran (BK) and offshore (ОFF), using 150 and 500 um mesh size. The parameters investigated were: surface and integrated temperature, salinity, turbidity, dissolved oxygen and chlorophyll a. Altogether 14 taxa were identified, and were distributed into two main groups: holoplankton and meroplankton. Copepods were the predominant taxon during all months. From 150 and 500 um samples they contributed about 79 and 37% at inshore station and 82 and 47% at offshore station, from the total zooplankton abundance, respectively. Noctiluca was observed in many of the 150 um samples at both stations. Station inshore showed the highest zooplankton abundances throughout the sampling periods, and had higher meroplankton ratios than the offshore station. Major peaks of zooplankton (particularly copepods) and Noctiluca scintillans abundances were observed on November 28th at both stations. Cluster analysis of zooplankton samples revealed two distinct groups, at a 60% similarity level. Most 90% of small samples are grouped together and well separated from large samples. ANOSIM analysis of the environmental variables suggested that both site were significantly different. For both 150 and 500 um samples, ANOSIM analysis on the abundance data suggested that the two stations showed different zooplankton taxa. BEST procedure identified four environmental variables out of ten as having a link to zooplankton composition, and it was significant for the 500 um size classes.