THE microalgal palynomorphs considered one of the main categories of non-pollen palynomorphs recognized in palynological slides which characterized by their potential paleoecological and stratigraphical values especially in the pre-Quaternary deposits. For this importance, four subsurface cutting samples recovered from two Cretaceous (Aptian/Albian and Turonian) geological units in Bougaz-1 well, northeast Sinai have been palynologically analyzed in order to study their algal content. Seven species of algae related to four genera from two divisions have been described and illustrated: Pediastrum boryanum, P. duplex, P. kawraiskyi, P. simplex, Scenedesmus acuminatus, and Chomotriletes minor (Chlorophyta); and Pterospermella sp. (Prasinophyta). Of these, two species (Pediastrum kawraiskyi and Scenedesmus acuminatus) are recorded for the first time from the Cretaceous of Egypt. Notes on the stratigraphic range and the geographical distribution of the most important recorded genera are given. The cell wall nature and its role in resistance to degradation are also discussed. The ecology of extant taxa has been used to determine the paleoenvironment and paleoecology prevailed in the studied area during the Cretaceous period.