Axillary osmidrosis often disturbs a person's social life, particularly in Asian countries. However, the clinical aspects of this condition have not been well documented in the English-language published work. This study aimed to provide information on the features of axillary osmidrosis, with a particular focus on sex differences. A retrospective review was made of the charts for 723 Japanese patients (492 female, 231 male). The mean age at initial presentation (29.1 years) was nearly the same for males and females. Almost all patients (96.1%) had wet earwax, which was extremely high compared to its frequency in the general Japanese population. An association with hyperhidrosis was seen in 61.8% of these patients. Subjective odor levels in female patients were significantly lower than those in males (P < 0.001). A positive family history was more frequent for females than for males (P < 0.001), and prior treatment history was also more frequent for females than for males (P < 0.015). Most patients (86.6%) had received some treatments in our clinic. There were significantly fewer females who underwent surgical treatments compared to males (P = 0.026), as females preferred less invasive techniques (P < 0.001). Several features, including male/female ratios, and associations of wet earwax and hyperhidrosis, corresponded to previously reported data on axillary osmidrosis. Female patients were more concerned with axillary odor than males, and females had a tendency for polysurgery.