This paper presents a general view of the telematic voting system developed by its authors, with a special emphasis on the important role that smart cards play in this scenario. The use of smart cards as basic pieces for providing secure cryptographic operations in this type of voting scheme is justified. The differences and advantages of Java Cards in comparison with the ?classical? smart cards (those that completely conform to the ISO/IEC 7816 standard) are also discussed. As an example, the paper describes one of the applets implemented in the voting Java Card as part of the general telematic voting application