The objective of this study is to analyze the guidance given by the existing pharmacoeconomic guidelines up to the sampling uncertainty. The aim is to focus on the existing degree of vagueness of guidelines in order to facilitate the tasks of those who must base their choices on studies of this kind. After the grouping of methods in an appropriate way so that there would be a relative correspondence with the guidelines, a selection of 22 guidelines was made to study the precision given to sampling uncertainty and the preferred methods of handling this uncertainty. The methods of handling uncertainty have plainly evolved in recent years. However, the differentiations in the guidelines concerning this field are considerable. Consequently, the tasks of submitters, evaluators, and decision makers become very difficult.