From both the methodological point of view and standardization of methodology, little attention has been paid to the estimation of direct costs in evaluation of healthcare technologies. The objective is to revise the recommendations on direct costs provided in European economic evaluation guidelines and to identify the commonalities and divergences among them. To achieve this, a comprehensive search through several online databases was performed resulting in 41 documents from 26 European countries, be they economic evaluation guidelines or costing guidelines. The results show a large disparity in methodologies used in estimation of direct costs to be included in economic evaluations of health technologies recommended by European countries. A lack of standardization of cost estimation methodologies influences arbitrariness in selecting costs of resources included in economic evaluations of medicinal products or any other technologies and, therefore, in decision making process necessary to introduce new technology. In addition, this heterogeneity poses a major challenge for identifying factors that could affect the variability of unit costs across countries.