Background: Suicide is the 11th leading cause of death in the USA. Suicide rates vary across ethnic groups. Whether suicide behavior differs by ethnic groups in the USA in the same way as observed for suicide death is a matter of current discussion. The aim of this report was to compare the lifetime prevalence of suicide ideation and attempt among four main ethnic groups (Asians, Blacks, Hispanics, and Whites) in the USA.Method: Suicide ideation and attempts were assessed using the World Mental Health version of the Composite International Diagnostic Interview (WMH-CIDI). Discrete time survival analysis was used to examine risk for lifetime suicidality by ethnicity and immigration among 15 180 participants in the Collaborative Psychiatric Epidemiological Surveys (CPES), a group of cross-sectional surveys.Results: Suicide ideation was most common among Non-Hispanic Whites (16.10%), least common among Asians (9.02%) and intermediate among Hispanics (11.35%) and Non-Hispanic Blacks (11.82%). Suicide attempts were equally common among Non-Hispanic Whites (4.69%), Hispanics (5.11%) and Non-Hispanic Blacks (4.15%) and less common among Asians (2.55%). These differences in the crude prevalence rates of suicide ideation decreased but persisted after control for psychiatric disorders, but disappeared for suicide attempt. Within ethnic groups, risk for suicidality was low among immigrants prior to migration compared to the US born, but equalized over time after migration.Conclusions: Ethnic differences in suicidal behaviors are explained partly by differences in psychiatric disorders and low risk prior to arrival in the USA. These differences are likely to decrease as the US-born proportion of Hispanics and Asians increases.