SUMMARY -Th e aim of this review is to analyze current diagnostic approaches to obesity in adult men, the potential mechanisms linking obesity to infertility, and treatment options aimed at improving reproductive health. Obesity has become a worldwide epidemic with the estimated prevalence increasing from 28.8% to 36.9% between 1980 and 2013. In terms of diagnosis, numerous simple techniques have been developed including body mass index, waist to hip ratio, waist circumference, bioelectrical impedance analysis, ultrasound and skinfold measurements. Additionally, several other less available but more accurate techniques have been suggested, such as air displacement plethysmography, dual energy x-ray absorptiometry, computed tomography and magnetic resonance imaging. In addition to cardiovascular and other disorders, male obesity can negatively aff ect the male reproductive potential through abnormal reproductive hormone levels, reduced semen quality, increased release of adipose-derived hormones and adipokines, as well as thermal, genetic and sexual mechanisms. In the management of obesity related male infertility, natural weight loss is the cornerstone and regular exercise the fi rst-line treatment. Although bariatric surgery results in greater improvements in weight loss outcomes when compared to non-surgical interventions, further research is required to clarify its overall infl uence on male fertility.