The purpose of this study was to further our understanding of how individuals move down the pathway from first thinking about suicide to ultimately attempting to take their own lives by empirically testing the Three-Step Theory (3ST) in a sample of university students (n = 665). Results largely support the theory’s central propositions. First, an interactive model of pain and hopelessness accounted for substantial variance in suicidal desire. This result replicated in both men and women, and across age groups (i.e., below 35 and at or above 35). Also, as predicted, connectedness was protective against ideation in those high on both pain and hopelessness. However, contrary to our prediction, connectedness was similarly protective among everyone else. Finally, suicide capacity predicted suicide attempt history over and above current and lifetime suicide ideation. These findings provide further support to the 3ST.