Infertility is a major, worldwide problem that is affected, and mediated, by several factors, in particular, oxidative stress. Thus, the aim of this study was to evaluate the effect of lycopene supplementation on spermatogram and seminal oxidative stress. In this randomized, double‐blind, placebo‐controlled trial study, 44 infertile men with oligozoospermia were randomly divided into two groups: The experimental group was supplemented with 25 mg of lycopene, and the control group received placebo for 12 weeks. Anthropometric, physical activity and dietary assessment, semen analysis, total antioxidant capacity (TAC), malondialdehyde, and glutathione peroxidase were measured pre‐ and post‐intervention. At the end of the study, there was a significant increase in total sperm count and concentration in the lycopene group, and the latter total count remained significant after adjustment (p < .05). Intragroup analysis showed a significant increase in ejaculate volume, total sperm count, concentration total motility, nonprogressive, and nonmotility in lycopene group (p < .05). The TAC changes, in both groups, remained significant after adjustment (p < .05). Also, within‐group analysis showed a significant increase in TAC levels (p < .05). Lycopene supplement can improve sperm parameters and oxidative stress biomarkers in oligozoospermia infertile men; however, further studies with larger sample size and duration are required.