Background: AIDS is now known as a crisis throughout the world. Gastrointestinal parasites are the main causes of infections in HIVpositive patients. Objectives: This study aimed to investigate the prevalence of intestinal parasites in HIV-positive patients who referred to Ahvaz health centers, Ahvaz, Iran in 2012. Patients and Methods: This cross-sectional study was conducted on 200 HIV-positive patients of the Ahvaz health centers who selected by convenient sampling. Patients' demographics were recorded by a researcher-made questionnaire. Then, their fecal samples were collected and tested by using direct and concentrated formalin-ether and modified acid-fast staining. Data were analyzed by SPSS 19 software using Chi-square and ANOVA (analysis of variance) tests. Results: The prevalence of intestinal parasites was 48.8%, which shows a high prevalence in HIV-positive patients. There was a significant relationship between prevalence of parasite and variables of job, kind of health centers, history of diarrhea (P = 0.0001), education (P = 0.001), and age (P = 0.005), but there was no relationship with variables of CD4 + count (P = 0.293) and dyspepsia (P = 0.103). Conclusions: Given the prevalence of most gastrointestinal parasites, the HIV-positive patients show a weak immune system and higher sensitivity for infection particularly for opportunistic parasites. So, routine stool tests for detection of intestinal parasites are very useful for people with weakened immune systems.