Nephrotic syndrome (NS) is a clinical diagnosis with proteinuria, hypoalbuminaemia and oedema. NS is rare in children, and its incidence in The Netherlands is unknown. The aim of this study was to estimate the incidence of idiopathic NS in the Netherlands. All paediatric patients (age 0-18 years) with a newly diagnosed NS in the Netherlands were registered by the Dutch Pediatric Surveillance Unit during the years 2003 until 2006, secondary NS was excluded. All paediatricians filled out questionnaires about the first clinical findings of the patients and incidences were calculated. A literature review on incidences of childhood NS was conducted. The incidence of NS in children in the Netherlands in the years 2003 until 2006 was 1.52/ 100, 000 children/ year. The median age at diagnosis was 3.88 years with a mean age of 5.08 years. A significant male:female ratio of 2.04:1 was found. This prospective study of NS in the Netherlands revealed an incidence of 1.52:100, 000 children/year, and is similar to the incidences found all over the world.