The cross-cultural generalizability of the interpersonal theory of suicide was examined in this study. One hundred ninety-nine adults in an inpatient setting in Mexico completed the Personal Resources Questionnaire, Beck Hopelessness Scale, Interpersonal Needs Questionnaire, Acquired Capability for Suicide Scale, and Suicide Behaviors Questionnaire-Revised. Analyses revealed the interaction between perceived burdensomeness and thwarted belongingness did not predict suicide ideation. The interactions between perceived burdensomeness and thwarted belongingness and between perceived burdensomeness and acquired capacity significantly predicted suicidal behaviors, whereas the hypothesized three-way interaction did not. These findings highlight the importance of perceived burdensomeness in the development of suicidal behaviors among Mexican-origin adults.