The main problem with dried-salted fish (DSF) products is lipid oxidation. PUFA of fish oil is very easily oxidized, and sodium chloride is known to be a pro-oxidant. Many researchers have found that the products of lipid oxidation had negative effects on a variety of species, so we evaluated the effect of a desalting and defatting treatment on the lipid oxidation of Indonesian DSF. The dietary effect of untreated DSF, defatted DSF and desalted DSF on diarrhea, on the internal organs, on hepatic, serum, and urinary lipid peroxidation, and on hepatic and serum alpha-tocopherol were evaluated by using rats. The defatting treatment had a significant effect (p < 0.01) on reducing the lipid oxidation variables of the DSF sample and on protecting the rats from diarrhea. Compared with the rats in the casein group, these in the untreated DSF group had significantly higher values (p < 0.05) for hepatic, serum and urinary lipid peroxidation, but significantly lower values for hepatic and serum alpha-tocopherol. No significant differences were observed between the rats fed with casein and defatted DSF.