Hyperlipidemia refers to a series of serious health hazards caused by high blood lipid levels, such as atherosclerosis, coronary heart disease, and pancreatitis. Hyperlipidemia also has a relationship with male reproductive function. Epidemiological surveys in China show that the prevalence of hyperlipidemia in adult men is 22.2%, and the incidence is increasing year by year. Hyperlipidemia has several effects on male reproductive function as follows. (1) Hyperlipidemia can affect spermatogenesis and reduce semen quality Hyperlipidemia can affect the secretory function of testicular interstitial cells, leading to a decrease in the synthesis of androgen-binding proteins and insufficient testosterone in the varicoceles, thus hindering the production of sperm. Hyperlipidemia also has adverse effects on the maturation process of spermatozoa in the epididymis, among other things. In animal models fed a high-fat diet leading to the development of hyperlipidemia, changes in sperm volume, number, morphology, and viability can be observed, resulting in impaired fertility. (2) Hyperlipidemia can damage testicular and epididymal tissue structure Normal testicular and epididymal tissue structure and function are critical for maintaining male reproductive function. In morphological studies, hyperlipidemia has been shown to affect testicular and epididymal tissue structures in both humans and animals, including reduced testicular varicose duct diameter, altered germinal epithelial cycle, thinning of germinal epithelium and reduced number of germinal cells, and in severe cases, sperm block may occur. At the same time, the tissue structure of epididymis may also be changed, such as the morphology of columnar epithelial cells of epididymal tubules becomes smaller and the official lumen is enlarged. (3) Hyperlipidemia can also affect male gonadal hormone levels. Hyperlipidemia can cause a decrease in androgen synthesis, inducing erectile dysfunction and ejaculation disorders in men, and can also lead to sperm disorders, thus reducing male fertility and even causing infertility. Hyperlipidemia can affect the function of the hypothalamic-pituitary-testicular axis, manifesting as a significant decrease in the levels of testosterone, follicle-stimulating hormone and luteinizing hormone, which can cause testicular development disorders. In addition, hyperlipidemia can also lead to erectile dysfunction by inhibiting vascular endothelial cell function and decreasing the ability of vascular smooth muscle to respond to nitric oxide, resulting in insufficient vasodilation and reduced blood flow to the corpus cavernosum. On the other hand, hyperlipidemia can affect the peripheral cavernous nerves that innervate penile erection, thus affecting penile erection. By the advanced stage of hyperlipidemic lesions, atherosclerosis can occur in the cavernous arteries, resulting in luminal narrowing that affects blood flow. Hyperlipidemia has some adverse effects on male reproductive function. Lifestyle improvement of a high-fat diet and early intervention of hyperlipidemia may contribute to the health of the male reproductive system. In contrast, patients with male reproductive dysfunction who have comorbid hyperlipidemia should be actively treated for hyperlipidemia to keep lipid levels under ideal control.