Objectives - The prevalence of certain chronic conditions is high among people living in extreme poverty. The objectives of this study are to estimate the prevalence of diabetes among people staying in emergency shelters and to describe the characteristics of those already diagnosed. Method - Diabetes screening was systematically offered in nine Parisian emergency shelters from October to December 2006. Nurses collected sociodemographic data and performed anthropometric measurements, capillary tests, and fasting blood draws. A clinical examination and a medical questionnaire were administered by a physician to individuals known to have diabetes. Results - Among the 488 participants, 35 reported having diabetes and 2 were newly diagnosed. The prevalence of treated diabetes was estimated at 6.1% (95% CI [2.4–9.8]), compared with 4.9% [4.8–5.1] among social security beneficiaries over the age of 20. One-quarter of people with diabetes had at least one macrovascular complication; 32% had retinopathy and 21% had received ophthalmic laser treatment; 17% had undergone an amputation, 6% had lower limb arteritis, and 35% had a high podiatric risk. Conclusion - This study highlights the severity of diabetes among people in extremely precarious circumstances and calls for an adaptation of their care, particularly podiatric care. (R.A.)