Plankton studies are one of the major items of the marine scientific activities in the ROPME Sea Area, whereas numerous investigations have been conducted on the plankton during the past century. For phytoplankton, species composition, abundance and biomass, primary production, harmful algal blooms, red tide, toxic species, and eutrophication were considered. Zooplankton studies included species composition and abundance, certain zooplankton groups and few studies on certain species. The main achievement of these studies was the identification of large number of phytoplankton and zooplankton species in different parts of the RSA and estimation of their abundance. The survey of these studies revealed the occurrence of several gaps in the plankton research in ROPME Sea Area. For example, the majority of these studies were carried out in the inner part, while some of them were done in the middle part. Several studies were based on samples collected once only during certain time of the year or on samples collected from localized areas. The role of the function groups of the both phytoplankton and zooplankton, the harmful algal blooms, toxic phytoplankton species, the role of small phytoplankton groups rather diatoms and dinoflagellates and vertical migration of zooplankton were little concerned. In addition, the continuous record of the Indo-Pacific species entering the inner RSA from the Sea of Oman appeared to be completely missed. The present study attempts to stress the achievements as well as the gaps in the earlier plankton studies in the ROPME Sea Area in order to propose a scientific plan for comprehensive study of plankton community relative to the prevailing environmental conditions in the concerned area.