Conducting surveillance of communicable diseases and/or public health surveillance in general, in developing countries such is B&H has some common specific things-health care system is an integral part of organized government services thus, fewer impediments to implementing any part of a surveillance system are recorded. Limited health care providers and laboratories reduce the number of data source and can facilitate quality assurance. An ideal surveillance system is discussed in this paper (what kind of surveillance system an epidemiologist would like to have in future), as well as barriers to the ideal surveillance system and technology of the future. Some elements of computerised public health surveillance system and surveillance of communicable diseases, particularly, are given (e.g. hardware, software, data entry, editing the data, analysis of data, ...) Computerising a surveillance system will results in increasing speed of processing providing graphic capability, enhancing analytic capabilities, improving quality of data of reports and improving quantity of data. The most important step in beginning to conduct computerising a surveillance system is identifying the public health objective such is, for example, surveillance of communicable diseases.