Nicotine (N) is known as the main toxic and addictive component of cigarette smoke. By its ability to generate reactive oxygen species (ROS) and oxidative damage in organism, it can induce major public health problems such as cancer, cardiovascular diseases and infertility. Green tea extract (GTE) is an important source of polyphenols catechins; it has attracted a great deal of attention around the world because of its potential antioxidants role in scavenging free radicals. This research was conducted to determine the potential role of green tea extract in attenuating the toxic effects that may be caused by nicotine on haematological and reproductive parameters in rat. Thirty-two adult Wistar male rats were randomly divided into four groups/8 for each. Group I served as control. Group II rats received orally GTE (2% w/v) as the sole drinking fluid. Group III rats were injected i.p. by nicotine (1 mg/kg bw). Group IV received i.p. nicotine (1 mg/kg bw) and GTE (2% w/v) concomitantly. After 2 months of treatment, blood samples were collected for measuring haematological parameters. Then, after necropsy, reproductive organs (testes, epididymes, and seminal vesicles) were removed, weighed and used for measuring semen quality and histology. The results show a decrease in red blood cells (RBC) count, haemoglobin and haematocrit with an increase in VGM in all treated groups as compared to control; while leucocytes (WBC) count has increased in nicotine group, diminished in GTE group and adjusted to normal values in GTE plus nicotine treated animals. Furthermore, nicotine decreases significantly the body weight gain and relative weights of reproductive organs; this toxic effect was removed by GTE coadministration. Sperm analysis and histological examination of testes revealed that nicotine reduced significantly sperm count, spermatid number, sperm daily production, motility, percentage of normal sperm morphology as well as induced histological alterations pronounced by atrophy, degenerative aspect of the seminal epithelium in some seminiferous tubules, large interstitial spaces with small number of leydig cells, perturbation in spermatogenesis leading to absence of spermatozoa and presence of cell debris in the lumen of some seminiferous tubules. All these adverse reproductive effects of nicotine were attenuated by GTE coadministration. It is concluded that GTE beverage produces a deleterious synergistic effect with nicotine on hematological parameters and plays protective role against nicotine-induced reproductive effects to improve semen quality and histological damage of testis.