The effect of mineral addition on γ -linolenic acid (GLA) production by Rhizopus nigricans SSSD-8 was studied. The cultivation was conducted at 30°C for 6 d in a 250 ml flask containing potato-dextrose-yeast medium with or without Na 2 SO 4 , CaCl 2 , MgCl 2 , NaCl and/or KCl. Cultivation in potato-dextrose-yeast medium without minerals produced 0.53g/L-culture of GLA, and the addition of 0.4% KCl increased the GLA production to 2.52g/L-culture. The addition of mineral mixture failed to increase the GLA production. The addition of mineral mixture, caused no change in triacylglycerol (TAG) and phospholipid (PL) compositions of the fungus. © 2003, Japan Oil Chemists' Society. All rights reserved.