The mobility of the prison population creates a need for information transmitted in transfers between centers that can guarantee optimal care continuity. To assess the quality of transmission of health information when inmates are transferred between prisons in Spain. Observational, descriptive and cross-sectional study, consisting of a review of medical records of inmates who passed through Madrid III Prison in a three-month period. All measured variables were qualitative, and were expressed in absolute and relative frequencies. 1,168 inmates passed through Madrid III Prison in this period. Only 21 came from prisons in Catalonia, the Basque Country or Navarre, where their medical records are different from those in the rest of Spain, and only 57.14% provided some type of health information. Of the remaining inmates, 70.79% provided some type of information: 63.90% of the total had prescriptions for medication and 5% were prescribed with methadone. Of those taking medication, 89.10% were prescribed it in electronic prescriptions, which were correct in 98% of the cases. For methadone, only 75.44% had electronic prescriptions, which were correct in all cases. The date of the last dose administered was only indicated in 72.40% of the treatments. Only 34.70% of the records presented optimal quality in terms of the information transmitted, and in 2.50% of the cases the information received was deficient. The use of computerized tools facilitates the transmission of information, reduces the workload and improves patient safety.