The wide use of potent antiretroviral therapy has significantly reduced mortality and morbidity in patients infected with the HI-Virus. Good individual tolerance and regular intake of an adequate drug regimen often lead to a substantial recovery of impaired immunologic function. In a substantial fraction of patients drug resistant virus is emerging. In the last decade transmission of such viruses to newly infected patients has been reported in several countries. Especially transmission of multidrug-resistant virus is of major concern. We report a case of a 25 year-old Swiss man with a newly diagnosed HIV-infection with a multidrug-resistant virus. In connection to this case we discuss the importance of resistance testing in newly diagnosed patients.