Curcumin and rosemary oil nanoemulsions (CUR and RON), having 184.3 nm and 158.3 nm average diameters, were successfully produced by a single sonication technique. Effectiveness of nanoemulsions against P. aeruginosa, E. coli, and S. typhimurium were tested by agar diffusion method. Total mesophilic bacteria (TMABc) growth in fish fillets treated with RON and CUR nanoemulsions was acceptable for human consumption up to the 9th day. Total psychrophilic bacteria counts (TPBc) in the fish fillets treated with RON and CUR was found to be lower (26% and 17%) than the control group samples, respectively. While TMAB growth in fish fillets treated with RON was effectively declined from 5.59 to 3.48 log CFU/g, TMAB count of the fish fillets treated with CUR was decreased from 7.42 to 6.53 log CFU/g during the analysis period. Therefore, the obtained novel nanomaterial could be effectively used to limit the rapid increase in bacterial spoilage of fish meat in the food industry.