MgO/MgAl2O4 nanocatalyst was synthesized by a simple, cost-effective and rapid method and used in biodiesel production from sunflower oil. MgAl2O4 was synthesized by combustion method at different fuel ratios and then active phase of MgO was dispersed on the samples by impregnation method. The nanocatalysts were characterized by XRD, FESEM, EDX, BET-BJH, TGA and FTIR analyses, so as to optimize the concentration of urea (as fuel) in the combustion synthesis. The physicochemical properties of the nanocatalyst confirmed the sample synthesized with fuel ratio of 1.5 has high surface area, effective morphology and texture properties. Finally, in order to evaluate catalytic activity of the samples in biodiesel production, the transesterification reaction was performed. The results indicated the catalyst prepared by combustion synthesis with a fuel ratio of 1.5 was optimum specifications for biodiesel production. Using this catalyst, 95% of sunflower oil was successfully converted to biodiesel. Furthermore, the optimal catalyst showed relatively good reusability, making it a good choice for industrial biodiesel production. (C) 2016 Elsevier Ltd. All rights reserved.