Objective The aim of this study was to explore the effect of testosterone deficiency on serum lipid levels and hepatic lipid accumulation in miniature pigs fed a high-fat diet (HFD). Methods Eighteen sexually mature male Chinese Wuzhishan miniature pigs (6~7 months old) were used in this study. The pigs were divided in three groups (n=6 animals/group) as follows: intact male pigs, castrated male pigs and castrated male pigs with testosterone replacement. They were fed a HFD diet for 12 weeks and body weights were recorded weekly. Serum levels of testosterone, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) were measured. Hepatic TG and TC levels were also determined, and liver tissues were embedded in paraffin and stained with hematoxylin and eosin (H&E). Results (1) The body weights of pigs in each group were found to be linearly elevated over time. Though castrated pigs gained less weight than did pigs in the other groups, no significant differences were found between them. (2) Castration caused a significant decrease in serum testosterone levels in pigs. This effect was recovered by testosterone treatment. (3) Serum levels of TC, LDL-C and TG were significantly increased in castrated pigs. However, castration had no significant effect on serum HDL-C levels. Testosterone treatment reduced the increased serum lipids in castrated pigs. (4) Hepatic TG and TC contents in castrated pigs were also significantly higher than those in other groups of pigs. Testosterone treatment reduced the increased hepatic lipids in castrated pigs. (5) Compared with other groups of pigs, castrated pigs showed increased steatosis. However, testosterone treatment attenuated hepatic steatosis in castrated pigs. Conclusion Testosterone deficiency caused severe dyslipidemia, and increased hepatic lipid accumulation in miniature pigs fed a high-fat diet.