OBJECTIVE: To assess the degree of implementation of medication error prevention practices in Spanish hospitals. METHOD: Descriptive multicenter study of the degree of implementation of the safety practices included in the "Medication use-system safety self-assessment for hospitals. Version. II". Spanish hospitals that completed the questionnaire between October/2021 and September/2022 participated. The survey contains 265 items for evaluation grouped into 10 key elements. Mean score and mean percentages based on the maximum possible values for the overall survey, for the key elements and for each individual item of evaluation were calculated. The results were compared with those of the previous 2011 study. RESULTS: A total of 131 hospitals from 15 autonomous regions participated in the study. The mean score of the overall questionnaire in all hospitals was 898.2 (57.4% of the maximum possible score). No differences were found according to dependency, size or type of hospital, either in the overall questionnaire or in the key elements. The lowest values were found for key elements 8, 1 and 6, on competence and training of health professionals in safety practices (45.1%), availability and accessibility of essential information on patients (48%), and devices for administering drugs (52.3%). With respect to 2011, significant increases were found both in the overall questionnaire and in the key elements, except 5 and 7, referring to standardization, storage and distribution of medications, and environmental factors and human resources. Several evaluation items on the safe management of high-risk drugs, medication reconciliation, incorporation of clinical pharmacists into the healthcare teams and implementation of technologies that allow full traceability throughout the medication system, showed low percentages CONCLUSIONS: There has been appreciable progress in the degree of implementation of some medication error prevention practices in Spanish hospitals, but many proven efficacy practices recommended by the World Health Organization and safety organizations are still poorly implemented. The information obtained can be useful for prioritizing the practices to be addressed and as a new baseline for monitoring progress.