The present study aims to evaluate the effect of different concentration of natural auxin, Indole-3 acetic acid (IAA) on growth, lipid yield, PUFA and EPA accumulation in Nannochloropsis oceanica CASA CC201. It was observed that the, treatment with 10 ppm concentration of IAA resulted in high cell number 579.5 x 10(6) cells/ml than the control (215.5 x 10(6) cells/ml). Treatment with IAA at a concentration of 40 ppm gives the highest cellular lipid accumulation of 60.9% DCW than the control 31.05% DCW). Lipid yield is also found to be increased by the addition of 40 ppm IAA (319.5 mg/L) compared with the control (121.5 mg/L). EPA percentage is increased to 10.76% by the addition of 40 ppm IAA compared to the control (1.87%). (C) 2017 Elsevier Ltd. All rights reserved.