Background. Although osteoporosis is often viewed as a disease of women, studies show that osteoporosis also results in substantial morbidity, mortality, and financial expenses in men. Despite this burden, there is a paucity of research on knowledge and beliefs about osteoporosis in young men. Purpose. To determine the level of osteoporosis knowledge and beliefs in young men. Methods. Cross sectional self-administered survey of 78 men enrolled in a college physical activity class. Osteoporosis knowledge was assessed by correct identification of 12 items, 8 of which are commonly identified as osteoporosis risk factors for men. A risk factor knowledge score was calculated by summing the number of correct responses for all 12 items (possible scores ranged from 0 to 12). A five-point Likert-type scale measured the strength of men's beliefs about osteoporosis by asking four questions. "How concerned are you about getting osteoporosis?" "How likely are you to get osteoporosis?" "How responsible do you think a person is for getting osteoporosis?" "How serious is osteoporosis?" The scale ranged from 1 (not at all) to 5 (extremely). Descriptive statistics and frequency distributions were developed. Analysis was done using SPSS 15.0. Results. 91% were non-Hispanic White and 97.4% ranged in age from 18 to 23 years. 96.2% had heard about osteoporosis. The percentage of men who correctly identified osteoporosis risk factors was high for low calcium intake (94.9%), family history (89.7%), and a sedentary lifestyle (88.5%) while it was poor for scoliosis (57.1%), smoking (56.4%), corticosteroids (50.0%), small, thin frame (46.2%), and alcohol use (38.5%). The mean risk factor score was 8.09±1.66 (range 2 to 12). Men believed that osteoporosis is a serious disease (mean 3.74±.87). However, men were not concerned about getting osteoporosis (mean 1.72±.82) and did not believe that they were likely to get osteoporosis (mean 1.78±1.78). Men also believed that one is not responsible for developing osteoporosis (mean 2.85±1.0). Conclusions. The knowledge and beliefs data from this study in young men are similar to previous studies in young women. Osteoporosis risk factor knowledge in young men tends to be poor for the majority of risk factors and men do not believe one is responsible for, likely to get, or concerned about osteoporosis. Osteoporotic hip fracture rates in men are projected to triple by 2040. The results of this study suggest that there is a public health need to provide educational osteoporosis prevention programs targeting young men.Keyword(s): disease prevention/wellness, health education college/univ