A cross-sectional study was conducted in Mwanza, Tanzania, to determine the burden of HIV and parasitic co-infections among patients who were confirmed or suspected cases of pulmonary tuberculosis (PTB). Of the 655 patients investigated, 532 (81.2%) had been confirmed as PTB cases, by microscopy and/or culture (PTB+), whereas the other 123 (18.8%) were only suspected cases, on the basis of other clinical criteria (PTB-). Hookworm and Schistosoma mansoni infections were common in the patients, with prevalences of 18% and 34%, respectively. Malarial, Ascaris lumbricoides, Trichuris trichiura and Strongyloides stercoralis infections were less common, each recorded at a prevalence of <5%. The PTB+ patients were less likely to be HIV-positive than the PTB- patients (43.6% v. 62.6%; P<0.0001). Among the PTB+ patients, the HIV-positive had a significantly lower prevalence (12.1% v. 25%; P<0.0001) and mean intensity (49 v. 123 eggs/g; P=0.003) of hookworm infection than the HIV-negative. The PTB patients in the study area were, however, still frequently co-infected with HIV and with parasitic infections that may increase morbidity and accelerate the progression of HIV disease.