Objective The aim of this study was to describe the health and social conditions of arrestees, as compared to the general population. Methods We studied a sample of 600 adult arrestees in three locations in the Greater Paris area, prospectively included (February–May 2013). A descriptive analysis has been performed, then prevalence was estimated using an indirect standardisation according to age, based on data from a population-based, representative survey in the same area. Results Arrestees had a median age of 31 years; 92% were males. As compared to the general population, arrestees had a lower level of education (8.6 vs. 7.6%, p < 0.001), were more frequently unemployed (42.0 vs. 11.9%, p < 0.001) and in a difficult financial situation (43 vs. 11%, p < 0.001) and had less significant social support (48.1 vs. 87.9%, p < 0.001). They reported also more frequently a chronic health condition (54 vs. 36%, p < 0.001) and a limited health insurance coverage (36 vs. 15%, p < 0.001). Conclusion Comparative analysis of male arrestees and males from the general population showed that the former had worse social and health conditions. These results argue for widespread medical interventions on all arrestees. Medical examination during detention could act as a gateway to health care and social support.