It is proposed that an analogous alteration to female menopause occurs in mid-life in men. The condition is often termed 'late-onset hypogonadism' (LOH), and it includes declined testosterone (T) production with an array of symptoms (e.g. reduced sexual function, depression, fatigue, insomnia, muscle weakness, irritability). The existence of LOH is highly debated with opinions of experts ranging from enthusiasm to total denial. The real nature of LOH has slowly started emerging through recent investigations, including the EU-supported multi-national European Male Ageing Study (EMAS). EMAS confirmed that, after 40 years of age, circulating T levels of men decline on average by 1% per year, but the decline is mainly due to obesity and chronic diseases. The strict EMAS criteria for the LOH include specific sexual symptoms (decreased sexual thoughts and morning erections, and erectile dysfunction) associated with low T levels. By these criteria the frequency of LOH is much lower than proposed by most earlier studies, only 2.1% in 40–79 year-old men. Increase of body-mass index from normal to mild obesity (25–30 kg/m2) suppresses T more than ageing from 40 to 80 years. Because LOH is usually caused by modifiable conditions such as obesity and chronic diseases, it is more logical to address them first before embarking on T replacement therapy, whose long-term effects and side-effects remain largely unknown. The old truths, i.e. avoidance of obesity and healthy life-style, with physical exercise and healthy diet, are the best ways to avoid LOH and to meet the challenges of ageing.