Increasing evidence supports a role for fish oil (FO) and the n-3 polyunsaturated fatty acids (n-3 PUFA) -docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in protecting against neurodegeneration. However, experimental evidence on their neuroprotective efficacy in neurotoxin models is rather limited. In the present study, we examined whether pretreatment with n-3 PUFA in SH-SY5Y cells and FO prophylaxis in rats would render them less susceptible to 3-nitropropionic acid (a mitochondrial toxin, NPA) exposure. Cells pretreated with DHA/EPA were more resistant to NPA-induced perturbations in antioxidant defenses and exhibited higher survival rate. Further, we validated these findings among growing rats provided with FO (4 mL/kg bw) prophylaxis for 4 weeks and subjected to NPA challenge (25 mg/kg bw/d during last 4 d). Interestingly, FO prophylaxis offered significant protection against NPA -induced oxidative dysfunctions and depleted dopamine levels in striatum. Based on our in vitro and in vivo findings, we hypothesize that the protective effect of FO may be wholly or in part related to its potential to enhance GSH, thiols and antioxidant defenses in specific regions of brain of rats. Thus FO prophylaxis is likely to offer a therapeutic advantage as a neuroprotective strategy under oxidative stress-mediated neurodegenerative conditions.