After specifying the meanings to be attributed to the analysis of government policies, the author examines in this article the relationships which must exist between the analysis of policies and the analysis of values. Inspired by the works of Rein and Vickers, he concludes that the analysis of policies and of government programmes must necessarily take into account the relationship between the values which underly the collective choices, the instruments reserved for insuring the implementation of these and, finally, the results of applying these instruments. Discussing the particular combination of the decision theories, the author concludes that the policy analyst must consider the rationality of the actor or of the decision-maker within the framework of the steps that the latter takes in order to make choices or reach decisions.