<p>Given the rapidly depleting supply of fossil fuels, rising fuel prices, and growing concern over global warming linked to fossil fuel combustion, microalgae are a promising feedstock for the generation of biodiesel. Light is an important environmental factor that has effect on the growth and accumulation of biomolecules in microalgae. Application of appropriate light intensity during microalgae cultivation is an important step towards achieving high biomass and lipid accumulation. In this study, light intensity was optimized during cultivation of <i>Tetradesmus dimorphus</i> to achieve efficient high biomass and lipid production. The maximum growth rate of 0.89±0.01 day^-1 and biomass yield of 0.27±0.08 g L^-1 day^-1 were achieved by culture cultivated under 80 µmol photons m^-2 s^-1. The maximum oil contents and lipid productivity were 24.20±0.07 % and 65.34 ±0.08 mg L^-1 day^-1 respectively at 80 µmol photons m^-2 s^-1. The results of the GC-MS showed that the major fatty acids formed were C₁₆ and C₁₈ which are suitable for biodiesel production. Monounsaturated fatty acids decreased progressively with increase in irradiance. Relatively lower irradiance of 40 and 80 µmol photons m^-2 s^-1 favored the production of saturated fatty acids while higher irradiance of 120 µmol photons m^-2 s^-1 enhanced the production of polyunsaturated fatty acids more than lower light intensities. The results of the biofuel properties obtained from the empirical calculations are within the specifications provided by EN 14214 and US ASTM D6751−02 biodiesel standards.</p>