The influences of nanoemulsions based on citrus peel (orange, lemon, mandarin, and grapefruit) essential oils on the biogenic amine (BA) formation in rainbow trout (Oncorhynchus mykiss) fillets stored 4 +/- 2 degrees C were investigated. The results demonstrated that main BAs in the trout fillets were putrescine, cadaverine, spermidine, spermine, serotonin, tyramine, dopamine, and agmatine. It was determined that nanoemulsion application had generally suppressive effect on the formation of BAs during storage. It was also found that especially orange and lemon nanoemulsion groups were effective on histamine formation. Histamine values ranged from 0.00 to 4.08 in all groups during storage and the levels were below the limit values of FDA and EU throughout the storage period for all treatment groups. Similarly, Quality Index (QI) values of BAs were found to be below legal limits in all groups. Consequently, it was found that nanoemulsions prepared from essential oils kept the BA formation at a lower level during storage.