The use of decision analysis is discussed as it relates to pharmacy practice. Decision analysis is a valuable approach to selecting a choice from among several uncertain alternatives. It encourages the practitioner to define his views explicitly and weigh the merits of each alternative. The decision maker lists the choices or options to be considered. These choices are incorporated into a decision tree with their probability of occurrence and the relative worth of each potential outcome (utility) to the concerned party. A limitation of the method is that utility values and probabilities are often estimated on the basis of the decision makers' biases. Examples of applying decision analysis to clinical and administrative choices in pharmacy practice are presented.