Surface Copepod samples were taken across Port Kilindini (Likoni Ferry), Mombasa, during April, June, August, October, December 1985 and February 1986, including six 24-h series and analysed for relative abundance. Changes were observed among abundant species of copepods, namely Corycaeus, Acrocalanus, Oithona, Acartia, Oncaea, Centropages, and Temora spp., and Macrosetella gracilis. A regular, predictable cycle caused by the spring-neap tidal and high-low tidal cylce was revealed. The night/day differences were a striking feature which was evident from the samples. Includes species that are new records in the West Indian Ocean