Objective: This was a cross-sectional study carried out amongst resident doctors training at the Aga Khan University Hospital, Nairobi to determine their bone mineral density and investigate for any association between the bone mineral density and the residents’ lifestyle. Methods: 65 randomly selected residents from various departments in the Aga Khan University Hospital, Nairobi, underwent a Dual Energy X-ray Absorptiometry (DXA) scan and filled out questionnaires to assess their physical activity, sunlight exposure and calcium intake. This was carried out between April and June 2011. Results: 65 residents were included in the final analysis. 50 residents (76.9% with a 95% CI = 65% – 85%) were found to have a low bone mineral density while 15 (23.1%) were normal. No significant association was found between the various residents’ lifestyle factors and their bone mineral density. Logistic regression analysis showed an association between increasing age and low BMD (p value = 0.038). Conclusion: There is a 76.9% prevalence of low bone mineral density amongst residents at the Aga Khan University, Nairobi which was thought to be spurious due to reference database used in the BMD analysis. Attempts should be made in coming up with a local reference normative database for use in comparison of bone mineral density in the country.