Enhancement of oil yield by nitrogen deprivation is frequently warranted but accompanied with growth restriction of algae. The aim of this work was to enhance oil yield while maintaining growth to proceed simultaneously. Therefore, a series of nitrogen concentrations (0-150% relative to that in Bold Basal Medium) has been applied. It has been shown that 75% nitrogen (2.21 mM) was the optimum concentration for growth, oil and dry mass accumulation in local isolates of Chlorococcum humicola, Scenedesmus dimorphus, Scenedesmus acutiformis and Scenedesmus quadricauda as well as incompletely deprived nitrogen (TAP medium) in the case of Chlamydomonas reinhardtii (SAG). Malonate (10 mM) and nitrogen (2.21 mM), which induced the highest biomass and oil yield, separately, were applied in combination. This combination induced further enhancement in oil and dry mass yield and the magnitude of enhancement was depending on the studied alga. Malonate enhancement of oils could be ascribed to its derivative malonyl CoA, the precursor of longer chain fatty acids. Or, due to its coherent characteristic as succinate dehydrogenase inhibitor that might lead to pyruvate accumulation and hence fatty acid synthesis. Oils and dry mass yield were increased due to increased biomass and percentage of oils in cellular dry mass. Chlamydomonas reinhardtii was the highest andScenedesmus acutiformis was the lowest with regards to oil yield and dry mass accumulation.