Changes in hepatic and ovarian superoxide dismutase (SOD) and catalase (CAT) activities, total antioxidant capacity (T-AOC) and malonyldialdehyde (MDA) contents in silver pomfret () during vitellogenesis and the responses of their levels to dietary n-3 long-chain polyunsaturated fatty acids (LC-PUFA) were investigated. Four iso-nitrogenous, iso-energetic and iso-lipidic experimental diets were formulated:(1) 100% fish oil (FO); (2) 70% fish oil and 30% soybean oil (FSO); (3) 30% fish oil and 70% soybean oil (SFO); and (4) 100% soybean oil (SO). Female silver pomfrets (1 year old) were assigned to one of the four diets (with three replicates each) for 185 d. The results showed that there was an increase in SOD and CAT activities, T-AOC levels and MDA contents in the liver and ovary during vitellogenesis, and that the levels of all the indices in the post-vitellogenesis stage were significantly higher than those in thepre-vitellogenesis stage (<0.05). No significant differences in hepatic SOD (except in the SO diet group) and CAT activities, T-AOC levels and MDA contents were found between the vitellogenesis and pre-vitellogenesis stages (>0.05). However, ovarian SOD and CAT activities, and T-AOC levels in the FO and FSO diet groups at the vitellogenesis stage, were significantly higher than those at thepre-vitellogenesis stage (<0.05). The highest levels of hepatic and ovarian SOD and CAT activities during vitellogenesis were found in the FSO diet group. At the post-vitellogenesis stage, hepatic and ovarian SOD and CAT activities in the FSO group were significantly higher than those in the SO group, respectively (<0.05); however, there was no significant difference between the FSO and FO groups (>0.05). No significant difference was found in hepatic and ovarian T-AOC levels among the diet groups at the pre-vitellogenesis stage (>0.05); however, at the post-vitellogenesis stage, the hepatic and ovarian T-AOC levels in the FO and FSO groups were significantly higher than those in the SO group (<0.05), while there was no significant difference between the FO and FSO groups (>0.05). The MDA contents in the liver and ovary increased with increasing dietary n-3 LC-PUFA, and this trend was more apparent in the liver tissue. There was no significant difference in ovarian MDA contents among the diet groups during vitellogenesis (>0.05), except for the FO group, which showed a significant increase at the vitellogenesis and post-vitellogenesis stages (<0.05). Statistical analysis showed that tissue antioxidant levels increased gradually during vitellogenesis, and the optimum dietary n-3 LC-PUFA content (4.01%, FSO group) could promote the tissue antioxidant levels in silver pomfret at the vitellogenesis and post-vitellogenesis stages. The results of two-way ANOVA indicated that statistically significant effects of both diets and stages were observed for the tissue antioxidant levels (<0.01). Meanwhile, the significant effects of interactions of diets and stages on the hepatic T-AOC levels and MDA content were also recorded (<0.05).