A cross sectional survey was conducted to determine the association between enteric parasites and diarrhoea in HIV-infected adults in Caracas. Three hundred and four patients were evaluated: 104 had acute diarrhoea, 113 chronic diarrhoea and 87 were controls. Isopora belli infection was associated with acute (P = 0.022) and chronic diarrhoea (P = 0.003), Entamoeba histolytica/dispar infection was also associated with both acute (P = 0.015) and chronic diarrhoea (P = 0.017). Strongyloides stercoralis (P = 0.003), and Cryptosporidium parvum (P = 0.017) infections were associated mainly with chronic episodes. Weight loss (P < 0.001), a non-infectious factor investigated, was significantly associated with diarrhoea. Eosinophilia, a laboratory parameter studied, was found to be associated with strongyloidiasis (P = 0.001), giardiasis (P = 0.001) and isoporiasis (P = 0.003). In summary, the presence of enteric parasites in HIV-infected patients from tropical urban areas with diarrhoea, with or without significant weight loss, must be considered. Similarly, eosinophilia might suggest parasitic infection in these patients.