A health institution based cross-sectional study was carried out in Shashemene town, Southern Ethiopia between September, 1993, and January, 1994, to determine the sero-prevalence and the clinical impact of HIV among newly diagnosed tuberculosis patients. The HIV-antibody was determined using the two ELISA procedures (Wellcozyme, Wellcome Diagnostics, Dartford Kent England, and Du-pont assay, Singapore). A total of 450 tuberculosis patients aged 15 years and above were enrolled in the study. The overall HIVseroprevalence rate was 44.4%. The highest rate was observed in the age group 20-39 years. A slightly higher HIV-infection rate was found in males (46%) than in females (41%). Those divorced and widowed patients had higher proportion of HIV seropositivity. The HIV positivity rate was higher for extra-pulmonary than pulmonary form of tuberculosis (OR = 3.80; 95% CI: 1.49, 9.7 ). Higher proportion of sputum positive patients were HIV-positive compared to the sputum negative pulmonary tuberculosis patients (OR=l. 09; 95% CI: 0.64,1.85) though they manifested typical radiographic features (OR = 7.87; 95% CI: 4. 39, 14.21) . vi Significant differences were noted among HIV positives than HIV negatives in manifesting herpes zoster, lymphadenopathy, oral candidiasis, peripheral paraesthesia and chronic diarrhoea . An alternat i ve diagnostic approach is required to avoid missing HIV-related tuberculosis which is communicable to the general population. Other findings are discussed and recommendations made.