This study aimed to assess the influence of smoking duration and intensity on sperm vitality, sperm DNA fragmentation, reactive oxygen species (ROS) and zinc (Zn) levels in oligoasthenoteratozoospermic (OAT) men with varicocele (Vx). A total of 246 men were investigated who were divided into OAT nonsmokers, OAT smokers, OAT nonsmokers and OAT smokers with Vx. They were subjected to history taking, clinical examination and semen analysis. In their semen, sperm hypo‐osmotic swelling (HOS) test, sperm DNA fragmentation test, seminal ROS and seminal Zn were assessed. The results demonstrated significantly decreased HOS test, seminal Zn level and significantly increased sperm DNA fragmentation, seminal ROS levels in OAT smokers with Vx more than OAT smokers compared with OAT nonsmokers. Smoking intensity, smoking duration and Vx grade demonstrated significant negative correlations …