Objective: Pet ownership is often assumed to have mental health benefits, but the effect of pets on suicide risk has a scant literature. Method: Using the interpersonal theory of suicide, we examined the relationships between perceived burdensomeness, thwarted belongingness, overall attachment to one’s pet (quality of the relationship), pet attachment avoidance (distrustful of the relationship) or anxiety (afraid of abandonment), and suicide risk. Three hypotheses were investigated: 1) higher levels of attachment would be associated with lower suicide risk via lower levels of thwarted belongingness/perceived burdensomeness, 2) lower levels of pet attachment would be associated with higher levels of suicide risk via attachment avoidance/attachment anxiety, and 3) attachment avoidance/anxiety would be associated with higher suicide risk via thwarted belongingness/perceived burdensomeness. Undergraduates (N = 187) completed surveys and indirect effect analyses were utilized. Results: Higher overall attachment was associated with decreased attachment anxiety, which was associated with lower suicide risk. Attachment anxiety was correlated with increased suicide risk. Overall attachment, attachment avoidance and attachment anxiety were not found to indirectly affect suicide risk. Conclusions: Findings suggest that pet ownership may provide both protective and deleterious effects in a nonclinical sample.