Objective: The aim of this article was to perform a narrative review of how pharmacogenetics and pharmacogenomics is being applied in the clinics, especially in Spain. Method: Publications and websites of major interest have been reviewed. Results: Pharmacogenes and variants used in several hospitals, available methodologies, and the implementation process are discussed. (c) 2023 Sociedad Espanola de Farmacia Hospitalaria (S.E.F.H). Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).