Osteoporosis, characterized by low bone mass and deterioration of bone tissue, is a significant public health concern worldwide in both male and female subjects, particularly among the aging population. Testosterone, the primary male sex hormone, plays a crucial role in bone health together with estrogens. This chapter aims to provide a comprehensive review of the relationship between testosterone and osteoporosis. It explores the impact of testosterone deficiency on bone mineral density and fracture risk, along with the mechanisms involved. Additionally, potential therapeutic interventions in men with osteoporosis are discussed, with specific attention to the impact of testosterone replacement therapy. The findings presented here contribute to our understanding of the complex interplay between testosterone and osteoporosis.