Here, in comparison with community-dwelling middle-aged and older men, we investigated the skeletal muscle mass and bone mineral density of a Japanese alpinist (Mr. A) who, at the age of 80 years, is to date the oldest person to have climbed to the summit of Mount Everest (8,848 m). Using dual X-ray absorptiometry, we determined the appendicular skeletal muscle mass index (SMI), total bone mineral density (tBMD), whole body fat-free mass index (FFMI) and fat mass index (FMI) of Mr. A (84.6 yr) and 209 community-dwelling middle-aged and older men (50-79 yr, mean age: 68.1 yr). The SMI, tBMD, FFMI and FMI were 8.79 kg/m2, 1.075 g/cm2, 22.3 kg/m2 and 9.8 kg/m2, respectively, in Mr. A and 7.46 ± 0.81 kg/m2, 1.020 ± 0.100 g/cm2, 18.1 ± 1.9 kg/m2 and 5.5 ± 1.7 kg/m2, respectively, in the community-dwelling middle-aged and older men. The values in Mr. A were higher than those in the community-dwelling middle-aged and older men, with z-scores for the SMI and tBMD of 1.63 and 0.55, respectively. Mr. A maintained a high skeletal muscle mass and bone mineral density even at the age of 84 years, which may have been attributable in part to his long-term training for mountain climbing.