The Netherlands Immunization Programme has greatly reduced the incidence of target childhood diseases and their complications. However, continuous vigilance is required. In this report we propose an integrated approach for surveillance of the Netherlands Immunization Programme. Data collection for all target diseases should be combined as much as possible. Such surveillance system has four key elements: . epidemiological surveillance . immunosurveillance studies . microbiological surveillance . surveillance of adverse events following vaccinations. The proposed primary surveillance system is considered suitable to collect the relevant data at the level of the general population. Specific studies in subpopulations can be further initiated on signals from the primary system.<br>