This paper studies the origin and evolution of three health archives at the Hospital de León that forms part of the Public Health Service of the region of Castilla and León (Spain). The principle of provenance is essential to decide upon the organisation of medical histories archives and all the documents included in them. The study assesses the management of the above mentioned health archives in order to highlight the importance of appropriate cataloguing, shelving and storage of medical records for an efficient day–to–day running of hospitals. The results will be useful in estimating the approximate cost of a proper archives management when taking into account factors such as patients staying longer than expected in hospital or the need to repeat medical tests