Objective: Human immunodeficiency virus (HIV) co-infection with parasitic diseases is an issue not only in parasite-endemic countries but also for persons who have migrated to more developed countries where the infections may go unrecognized due to lack of experience by the practitioners especially that the patients are often asymptomatic when parasite burdens are low. For this reason, we performed a systematic screening program for parasitic diseases in immigrant patients with HIV infection. The results of this program are described. Design: A cross-sectional study was conducted to evaluate the results of this screening program. Methods: Screening for all patients comprised blood count, biochemistry, basic urinalysis, CD4+ cell counts, HIV viral load and HIV-subtypes, Hepatitis B virus, hepatitis C virus, syphilis antibodies, and PPD test. Parasitological test included three concentrated stool samples, detection techniques for Plasmodium and serological detection of Schistosoma spp., Strongyloides and Chagas’ disease. Results: 63 patients were analyzed. Thirty-four patients had a parasitic disease. The geographical distribution of the patients was as follows: Central Africa (52.4%), South America (31.7%), West Africa (9.5%); North-Africa and Centro America (3.2% each). Thirty-four (54%) patients had a parasitic disease. The most frequent disease was intestinal parasites followed by filariasis and Chagas’s disease. Parasitic diseases were more frequent in patients from Central Africa (11 vs 22, p=0.033, OR 3.00 [0.95-9.62]) Twenty-eight patients (44.4%) were infected with intestinal parasites and in this case viral load was significantly higher in infected patients 287,970 ± 982,009 RNA viral copies/mm3 vs 83,616 ± 196,220, (p=0.041). In the rest there are no statistical differences in age, sex, and time in Spain and the average CD4+ cell count between infected and not infected patients. Conclusions: This study supports the use of screening for parasitic diseases in immigrant patients with HIV infection.