The objective of this article is to analyze the importance and the role of Information Security in online medical information systems. Healthcare organizations have to protect private information pertaining to the individuals they serve. As more and more healthcare organizations implement computer-based ERPs, telemedicine, EDI, data warehouses and other network-based information systems, information security in healthcare gains importance more than ever before. Possible questions and issues related to information security requirements might be: “How do the healthcare professionals protect the information in their EPR systems?”, “How can network data exchange and transfer over the Internet be accomplished without being tampered by hackers and other unauthorized individuals or groups?” To answer these questions, players in the healthcare chain (providers, physicians) are turning to computerized solutions. As one might recall, turning to computerized medical record systems was the solution for healthcare organizations some years ago. Now we are dealing with the problems that those computerized systems may bring.