This meta-analysis including 10 randomised controlled trials suggests that exercise is associated with a statistically significant, but relatively mild, improvement effect on bone mineral density in middle-aged and older men, indicating that exercise has the potential to be a safe and effective way toavert bone loss in men. To determine the effect of exercise on bone mineral density (BMD) in middle-aged and older men. We searched three electronic databases up to March 21, 2022. A systematic review of the literature according to the PRISMA statement included (1) randomised controlled trials (RCTs), with (2) at least one exercise group as an intervention versus a control group, (3) men aged ≥ 45 years old, and (4) areal BMD of the lumbar spine (LS) and/or femoral neck (FN) and/or total hip (TH) and/or trochanter region. Mean differences (MD) for BMD changes at the LS, FN, TH, and trochanter were defined as outcome measures. A total of 10 eligible RCTs were included (N = 555 participants). Exercise significantly improved BMD, and the summarised MD was 0.02 (95% CI: 0.00 to 0.05) for LS BMD, 0.01 (95% CI: 0.00 to 0.02) for FN BMD, 0.01 (95% CI: 0.00 to 0.01) for TH BMD, and 0.03 (95% CI: 0.00 to 0.05) for trochanter BMD. Subgoup analyses showed the improvement effect was statistically significant in trials with longer duration and higher intensity in LS (≥ 12 months: MD, 0.01, 95% CI:0.00 to 0.03; higher intensity: MD, 0.01, 95% CI:0.00 to 0.03) and FN (≥ 12 months: MD, 0.02, 95% CI:0.01 to 0.02; higher intensity: MD, 0.01, 95% CI:0.01 to 0.02). Our results suggested a relatively mild, improvement effect of exercise on LS and proximal femur BMD. Exercise has the potential to be an effective way to avert bone loss in middle-aged and older men.