Background. Human Immune Deficiency Virus (HIV/AIDS) continues to be an underrecognized risk for suicidal ideation, suicidal attempt, and completion of suicide. Suicidal ideation and attempt in HIV/AIDS is not only a predictor of future attempted suicide and completed suicide. Methods. An institution based cross-sectional study was conducted among HIV-positive patients attending HIV care at Zewditu Memorial Hospital. Systematic random sampling technique was used to recruit 423 participants from April to May 2014. Composite International Diagnostic Interview was used to collect data. Multivariable logistic regression was computed to assess factors associated with suicidal ideation and attempt. Result. Suicidal ideation and suicidal attempt were found to be 22.5% and 13.9%, respectively. WHO clinical stage of HIV, not being on HAART, depression, family history of suicidal attempt, and perceived stigma were associated with suicidal ideation. WHO clinical stage, being female, not being on HAART, use of substance, and depression were associated with suicidal attempt. Conclusion. Early diagnosis and treatment of opportunistic infections, depression, and early initiation of ART need to be encouraged in HIV-positive adults. Furthermore, counseling on substance use and its consequences and early identification of HIV-positive people with family history of suicidal ideation have to be considered.