ABSTRACT: BACKGROUND:Suicide which is considered a psychiatric emergency, is a serious cause of mortality worldwide. Youth living with HIV/AIDS (YLWHA) have higher rates of suicidal behavior than the general public. This study aimed to assess the magnitude and associated factors of suicide ideation and attempt among the Human Immune deficiency Virus (HIV) positive youth attending anti-retroviral therapy (ART) follow up at St. Paul`s hospital Millennium Medical College and St. Peter`s specialized hospital, Addis Ababa, Ethiopia. METHODS:In this cross-sectional study, 413 HIV positive youth were recruited for interviews, using the systematic random sampling technique. The Composite International Diagnostic Interview (CIDI) was used to assess suicide. PHQ-9, the Oslo social support and HIV perceived stigma scale instruments were used to assess the factors. We computed bivariate and multivariable binary logistic regressions to assess factors associated with suicidal ideation and attempt. Statistical significance was declared at P-value <0.05. RESULT:The magnitude of suicidal ideation and attempts were found to be 27.1% and 16.9%, respectively. In the multivariate analysis, female sex (adjusted odd ratio(AOR) = 3.1, 95% CI, 1.6-6.0), family death (AOR = 2.1, 95%CI 1.15-3.85), WHO clinical stage III of HIV (AOR = 3.1 95% CI 1.3-7.35), WHO clinical stage IV of HIV (AOR = 4.76, 95%CI, 1.3-7.35), co-morbid depression (AOR = 7.14, 95%CI, 3.9-12.9), and perceived HIV stigma (AOR = 4.2, 95%CI, 2.27-8.2) were significantly associated with suicidal ideation, whereas female sex (AOR = 4.12, 95%CI, 1.82-9.78), opportunistic infections (AOR = 3.1, 95%CI, 1.6-6.04), WHO clinical stage III of HIV (AOR = 3.1 95%CI 1.24-7.81), co-morbid depression (AOR = 5.6 95% CI, 2.8-11.1), and poor social support (AOR = 3.4, 95%CI, 1.2-9.4) were statistically significant with suicidal attempt. The result suggests that the magnitude of suicidal ideation and attempts among HIV positive youth were high. We recommend that clinicians consider youth with comorbid depression, perceived HIV stigma and poor social support.