In people living with human immunodeficiency virus (HIV), several complaints related to the gastrointestinal system, mainly diarrhea can be determined. In our study, we aimed to detect the existence of intestinal parasites with conventional methods based on microscopy and with molecular methods based on multiplex-PCR among 90 anti-retroviral treatment (ART) naive or ART adherent HIV/AIDS cases. The existence of Giardia spp., Blastocystis spp., Entamoeba histolytica, Dientamoeba spp. and Cryptosporidium spp. were searched in stool samples and the relation with the existence of these parasites and demographic/clinical data of the cases were determined. The demographic and clinical data of the participants included in the study were as follows; the average age was 34.02 +/- 9.7 years, average time of diagnosis was 2.4 +/- 1.7 years. Gender distribution was as follows; 85.6% male and 14.4% female. HIV transmission was related with heterosexual intercourse in 60%, homosexual intercourse in 33.3%, blood/blood products contact in 1.1% and with unknown routes in 5.6% of the cases. Fifty percent of the patients were in pre-ART and 50% was in on-ART state. The average CD4+ T lymphocyte count was detected as 400 cells/mm(3) and the median of viral load was 114.527 copies/ml. An overall prevalence of at least one intestinal parasitic infection was recorded as 36.7% and the prevalence of this infection due to Blastocystis spp. was 22.2%, followed by Dientamoeba spp. (13.3%), E. histo lytica (4.4%), Cryptosporidium spp. (3.3%), Giardia spp. (2.2%) and multiple parasitic infections (7.7%). The type of sexual behaviours related with the detection of intestinal parasites were statistically significant especially in homosexual intercourse (p< 0.001). The increase in CD4+ T lymphocyte counts were reversely associated (p= 0.062) and the increase in the levels of viral load were positively associated (p< 0.001) with detection rate of intestinal parasite. The detection of parasites by molecular methods was statistically significant in pre-ART participants (p= 0.002) and participants with diarrhea (p= 0.019). In the present study, the increase in the frequency of intestinal parasitic infections has shown that essential interventions are required. In all HIV/AIDS cases, routine parasitic screening should be performed by more sensitive methods to manage early and specific treatment.