Tuberculosis (TB) is the leading cause of morbidity and mortality among people living with HIV/AIDS worldwide, particularly in developing countries. Prevalence and known risk factors for TB among HIV-infected patients vary from one setting to another. A cross-sectional study was carried out from January to March 2018 in order to determine the prevalence of TB and associated risk factors among HIV/AIDS patients attending the HIV clinic at Aysaita Primary Hospital in the Afar region of Ethiopia. A total of 403 HIV positive patients were included and sputum samples and other relevant data were collected using structured questionnaire and from patients’ history cards at HIV clinic and Statistical tests analyzed.In the present study, out of 403 HIV seropositive patients, 251 (62.3%) were found to the proportion with tuberculosis. Among the proportion of TB in HIV patients, 91.2% were pulmonary tuberculosis positive (PTB + ve) and the remaining 22 (8.8%) were Extra pulmonary tuberculosis. WHO clinical stage III of AIDS (AOR: 4.079, 95% CI (1.108 - 15.022), WHO clinical stage IV of AIDS (AOR: 2.792, 95% CI (1.004 - 7.764) and previous history of TB infection (AOR: 0.266, 95% CI (0.099 – 0.715)) were important determinant factor of tuberculosis among HIV infected patients (P<0.05). However, risk of TB was not independently associated with socio demographic characteristics, knowledge, attitude and practice and some risk factors (P<0.05). In conclusion, the prevalence of TB/HIV co-infection at Aysaita primary Hospital was quite high. The co-infection was associated with WHO clinical stage III, IV and history of TB infection. Besides, Provision of health education about modes of transmission of TB and other opportunistic infectious diseases to HIV/AIDS patients is necessary. Keywords: M.tuberculosis, HIV, proportion, Aysaita, Ethiopia