Objective: The objective of this study is to describe the process of creation and development of the quality certification standard for pharmaceutical care for outpatients of the Pharmacy services. Method: The methodology was carried out by a group of experts from the Spanish Society of Hospital Pharmacy (SEFH) and consisted of three phases: situation analysis, development of the standard and definition of the self-assessment tool and, finally, piloting in several hospitals, determining its feasibility, carrying out a new revision and readaptation. Results: A standard was defined with 118 items distributed in ten areas. Of these, 19 were considered compulsory, 36 basic, 40 medium and 23 advanced. Three levels of certification were established, as well as the definition and percentages of compliance with the requirements. The certification process was divided into two stages, the one of previous preparation and the audit itself, where the initial certification would be covered, with four phases-first three led by the certification Company, and the last one by SEFH and the subsequent follow-up and re-certification audits. Two hospitals piloted the process carried out the piloting of the whole process, both obtaining a basic level after the adoption of measures and corrective actions, after which the final definition of the external evaluation of the standard and the name of the standard was agreed upon "Q-PEX", as well as, the registration of the intellectual property of said standard in July-2020. Conclusions: The standard for certification of the quality of pharmaceutical care for outpatients developed aims to help the continuous advancement of Hospital Pharmacy services.