We present the results of the study carried out by The Spanish Society of Penitentiary Health Working Group on Infectious Diseases (GEISESP) on the opinion of prison doctors concerning the suitability of undertaking or not undertaking controls of HIV infection in prisons and about the difficulties, efforts, needs and responsibilities that this activity may involve. This study was carried out in 2007 using an ad hoc survey designed and sent to doctors at 73 prisons in Spain. 116 valid questionnaires were received. It was considered that the data received could be applied to the whole population with a level of trust of 95% and an 8% margin of error. Half the doctors referred to prescribing antiretroviral treatments, though only 10% admitted prescribing rescue combinations. It should be noted that only of half the doctors consider themselves to be appropriately prepared to deal with patients infected by the HIV virus, though half of them admit to having received specific postgraduate training on this subject. Generally speaking, doctors consider that the quality of the health care received by the HIV-infected population is quite good.