This article applies constructs from the Self-Medication Hypothesis and Social Cognitive Theory to explain the development of substance use and psychological distress after a disaster. A conceptual model is proposed, which employs a sequential mediation model, identifying perceived coping self-efficacy, psychological distress, and self-medication as pathways to substance use after a disaster. Disaster exposure decreases perceived coping self-efficacy, which, in turn, increases psychological distress and subsequently increases perceptions of self-medication in vulnerable individuals. These mechanisms lead to an increase in postdisaster substance use. Last, recommendations are offered to encourage disaster researchers to test more complex models in studies on postdisaster psychological distress and substance use.