Adverse events following immunisation (AEFI) in the National Vaccination Programme of the Netherlands (RVP) have been monitored through an enhanced passive surveillance system by RIVM since 1962. From 1984 onward evaluation is done in close collaboration with the National Health Council. Reports from Health Care workers are recieved mainly by telephone through the operating vaccine information and advisory service. Further data are obtained, if necessary, from parents, general practitioners, paediatricians etc. After supplementation and verification of data a (working)diagnosis is made and causality assessed. In this report on 1995 an overview of all recieved AEFI is made and causality assessed. In this report on 1995 an overview of all recieved AEFI is presented with classification according to case definitions and causality. Reporting bias, background rates of specific events and possible pathophysiology of symptoms are discussed. On a total of approximately 2 million vaccinations 800 AEFI were submitted. Of these 1% (8) was unclassifiable because of missing information. In 81% (641) of the classifiable events a possible causal relation with vaccination was established and in 18% (151) the events were judged to be coincidental. Compared with 1994 there was again a rise in the number of notifications Thorough evaluation revealed no increase of true side effects in the Netherlands but a further decrease in underreporting.