The Free Center for Information, Screening, and Diagnosis of HIV, Viral Hepatitis, and Sexually Transmitted Infections (CeGIDD) in the Seine-Saint-Denis department is a partner of the Reception, Care, and Referral Center (Caso) run by Médecins du Monde (MdM) in Saint-Denis. Newcomers who come to Caso are invited to the CeGIDD’s off-site clinic at the MdM premises, where they are offered screening for HIV, hepatitis, and sexually transmitted infections. The weekly clinic for newly arrived migrants is staffed by a multidisciplinary team: a doctor, a nurse, with the assistance of interpreters and/or mediators, and in the presence of a social worker. We present the results of this clinic for the period 2012–2016. The results of this study show HIV seropositivity rates (3.6%) and hepatitis rates (HBV 10.9%, HCV 8.2%) higher than national rates, those of the department as a whole, and those of other departments in the region. This early screening initiative should enable faster referral and enrollment in a care pathway. These results confirm the relevance of initiatives in partnership with associations targeting newly arrived immigrants upon their arrival in France, with the aim of strengthening prevention, limiting the risk of infection, and facilitating access to care for those already infected.