OBJECTIVE: The aim of this article is to provide an outcome evaluation model for preparedness of pharmaceutical services (PS) in disaster situations. METHODS: A five-step evaluation model development was conducted. The first step was a search of disaster preparedness and PS literature. The second step consisted of a description of the political and organizational aspects, external context, implementation, and performance of PS in disaster preparedness. A theoretical model on PS preparedness in disaster situations, encompassing pharmaceutical services variables and measures of preparedness, was developed as the third step. The fourth step produced a comprehensive theoretical model for evaluating PS preparedness, combining the two approaches used in steps two and three. The fifth and final step examined the development of the indicator framework. RESULTS: The results of this methodological approach are presented in the logic model of PS preparedness and the indicator framework, both of which were developed based on the disaster preparedness and PS literature and organized to provide a structured evaluation approach. CONCLUSIONS: PS was conceptualized as a program that can be evaluated by measurable effects. These effects can only be measured based on documented, on-site conditions before and after an event recognized as a disaster situation. This conceptual approach is context-modulated and therefore only applicable where the logistic cycle has been adopted as the rationale for PS.