Historically, osteoporosis has not been considered a public health priority for the Hispanic population. However, recent data indicate that Mexican Americans are at increased risk for this chronic condition. Although it is well established that there is heterogeneity in social, lifestyle, and health-related factors among Hispanic subgroups, there are currently few studies on bone health among Hispanic subgroups other than Mexican Americans. The current study aimed to determine the prevalence of osteoporosis and low bone mass (LBM) among 953 Puerto Rican adults, aged 47 to 79 years and living on the US mainland, using data from one of the largest cohorts on bone health in this population: The Boston Puerto Rican Osteoporosis Study (BPROS). Participants completed an interview to assess demographic and lifestyle characteristics and bone mineral density measures. To facilitate comparisons with national data, we calculated age-adjusted estimates for osteoporosis and LBM for Mexican American, non-Hispanic white, and non-Hispanic black adults, aged ≥50 years, from the National Health and Nutrition Examination Survey (NHANES). The overall prevalence of osteoporosis and LBM were 10.5% and 43.3% for participants in the BPROS, respectively. For men, the highest prevalence of osteoporosis was among those aged 50 to 59 years (11%) and lowest for men ≥70 years (3.7%). The age-adjusted prevalence of osteoporosis for Puerto Rican men was 8.6%, compared with 2.3% for non-Hispanic white, and 3.9% for Mexican American men. There were no statistically significant differences between age-adjusted estimates for Puerto Rican women (10.7%), non-Hispanic white women (10.1%), or Mexican American women (16%). There is a need to understand specific factors contributing to osteoporosis in Puerto Rican adults, particularly younger men. This will provide important information to guide the development of culturally and linguistically tailored interventions to improve bone health in this understudied and high-risk population. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.