Background: Tuberculosis is the most common cause of death among people living with HumanrnImmunodeficiency Virus. The World Health Organization recommends that in countries wherernHIV prevalence is at least 1% among adults and 5% among Tuberculosis patients, allrnTuberculosis patients should be offered HIV testing and all People living with HIV should bernscreened for Tuberculosis. To increase uptake of HIV testing, it also recommends providerrninitiated HIV testing and counseling.rnObjectives: The objective of this study was to assess determinants of HIV testing amongrnTuberculosis patients on DOTS in East Wollega zone, Ethiopia.rnMethodology: Institution based case control study design was conducted from January â€“ Marchrn2011. Both quantitative and qualitative approaches were used. Cases were tuberculosis patientsrnwho have not accepted HIV testing while the controls were those who have accepted HIV testing.rnA sample of 270 (90 cases and 180 controls) tuberculosis patients, with a ratio of two controls tornone case, was used. Simple random sampling technique was used to recruit study subjects andrnSPSS Version 17 was used for quantitative analysis while verbatim was used for qualitative data.rnResult: Tuberculosis patients who have tested for HIV have heard their HIV test result in whichrn23(12.8%) of them were HIV positive and 157(87.2%) of them were HIV negative. The proportion of HIVrninfected individual was 10(13.2%) among males and 13(12.5%) among females, while its 19(16.4%)rnamong TB patients from urban and 4(6.2%) among those from rural area. Tuberculosis patients havingrnlow knowledge about HIV were more likely to reject HIV testing AOR 3.697 (CI 2.135, 6.402)rncompared to those who are knowledgeable about HIV. Higher level of stigmatized attitude towardrnHIV and being from urban were also associated with rejecting HIV testing AOR 3.421(CI 1.870,rn6.257) and AOR 5.692(CI 1.930, 16.783) respectively.rnConclusion: Efforts to promote HIV testing utilization require effective strategies to reducernstigmatizing beliefs towards HIV and PLWHA among TB patients. Health informationrndissemination regarding HIV testing and risky sexual behavior reduction should have to berntargeted most at risk population like tuberculosis patients.