Objective: Narcissism has extensive intrapersonal and interpersonal consequences and is a predictor of several forms of psychopathology. Pathological narcissism is considered as a risk factor for suicidal ideation (SI). This research aimed to examine the mediating role of emotion regulation deficits and rumination in the relationship between pathological narcissism and SI.
Methods: A total of 463 students (232 girls, 231 boys) from public universities in Tehran Province, Iran participated in this study. Participants completed the Brief-pathological narcissism inventory (B-PNI), difficulties in emotion regulation scale (DERS), ruminative response scale (RRS), and beck SI inventory (BSSI). 
Results: The results indicated that pathological narcissism was positively and significantly associated with SI, emotion regulation difficulties, and rumination (P<0.01). However, vulnerable narcissism (VN) showed stronger associations with these variables than grandiose narcissism (GN). Structural equation modeling indicated that emotion regulation difficulties significantly mediated the relationship between VN and SI (P<0.01).
Conclusion: These findings suggest that deficits in emotion regulation, particularly in the context of VN, play a key role in explaining SI among university students.