Dermestes maculatus is a major fish pest causing serious damage when left uncontrolled. This work identifies the fatty acids of Nigeria-obtained neem seed oil (NSO) and the potential of different mixtures of the NSO and iodized salt in the control of the pest. Seven fatty acids: palmitic acid (18.09%), linoleic acid (33.73%), stearic acid (14.37%), oleic acid (13.4%), octadecanoic acid (12.93%), 9, 12–octadecadienoic acid (1.47%) and arachidic acid (3.33%) were identified in the NSO. Percentage of D. maculatus adu1t mortality (100%) observed in fish treated with 0.00 μl NSO + 0.50 mg salt, 100 μl NSO + 0.125 mg salt and 0.00 μl NSO + 0.25 mg salt was significantly (p