The earliest significant contributions to the knowledge. of the plankton of the Red Sea were provided prior to the establishment of the State of Israel in 1948 by several foreign expeditions sponsored by their respective countries. Samples collected in the course of these expeditions included mainly the higher taxonomic groups of marine zoo-plankton. Shortly following the founding of the State of Israel, teams of Israeli scientists undertook sporadic visits to the northern part of the Gulf of Aqaba off Eilat ([1]) for the collection of biota, including plankton, and in conjunction with basic physical and chemical observations. During the International Indian Ocean Expedition in the 1960s, Israel achieved heightened recognition of the Red Sea as part of the study area on the basis of its work in the Gulf of Aqaba and other areas of this marine environment. The establishment of the Heinz Steinitz Marine Biological Laboratory in 1968 at Eilat and later the Marine Science Station at Aqaba, Jordan, in 1974 provided adequate bases for subsequent, more comprehensive long-term studies pursued in the Gulf of Aqaba in all fields of oceanography, including plankton. These are considered in chronological order over the following three decades, with emphasis on the nature and scope of the respective research programmes. Some salient features of the plankton emerge from these largely inter-disciplinary studies, with particular reference to the pelagic microbiota.