The objective of this study was to determine the effect of different concentrations of anolyte on saprolegniasis in comparison with green malachite in rainbow trout hatcheries, in the northern part of Iran, Tonekabon. Nearly 5000 green eggs of Oncorhynchus mykiss (equivalent to 300 g) were obtained from a private farm in the north of Iran. The study was designed in 5 treatments, 0.25, 0.5, 30 and 100 ppm of neutral anolyte and 2 ppm of green malachite and two controls including positive control, meaning that the green eggs were purposely infected with saprolegnia but without any disinfectant, and negative control, which was implied to as the untreated group, all in triplicate. There was no significant difference (α>0.05) in hatchability percent between 2 ppm of green malachite and the group treated with 0.25 ppm of neutral anolyte, contrary to other anolyte concentrations. It is concluded that constant use of 0.25 ppm of neutral electrolyzed oxidized water (NEOW) is a more effective anti-fungal solution with the least side effects in comparison with 2 ppm of green malachite.