The current study examined hypotheses related to the development of suicidal ideation as directed by the interpersonal theory within a sample of acutely suicidal psychiatric inpatients. Consistent with ideation-to-action models, we distinguished suicidal desire from resolved plans and preparations. Although thwarted belongingness and perceived burdensomeness were correlated with suicidal desire, only perceived burdensomeness was associated with suicidal desire controlling for depression and thwarted belongingness. Depression alone was related to plans and preparations. Findings are interpreted as challenging the mechanisms hypothesis of the interpersonal theory and suggest that alternative conceptualizations of the development of suicidal desire may be warranted.