A chip card based medical information system was developed as a good possibility to create a portable electronic patient record. The produced software module provides an on-line, portable diabetes medical record information system. In particular the patient data card makes the up-to-date patient's record available whenever needed. The developed Core System includes a patient record management system that has the ability to handle topics such as medical anamnesis, administrative, medical and physical examination data. Issues tackled were simplicity, data security and reporting. Customization and internationalization were also covered by presenting a novel approach using native initialization files. Proper care has been addressed during the development of the software modules for matters of security, data integrity and confidentiality.