Introduction. Eighty percent of children with primitive nephrotic syndrome (NS) will have at least one relapse in their life. Specific risk factors could be associated with a higher incidence of relapses and a worse prognosis. This study aims to deepen the demographic and onset-related risk factors in children with known diagnosis of primitive NS attending the Pediatric Nephrology Unit of the University Hospital of Padua. Methods. Observational, descriptive study of all children (1-11 years old) with a known diagnosis of Primitive NS who attended our Pediatric Nephrology Unit between 1 January 2002 and 31 March 2023. Results. 49 patients were involved. 79.5% had at least one episode of NS relapse during their lifetime. 69.4% were classified as frequently relapsing or steroid-dependent NS. The relapse risk factor "non-Western ethnicity" was related to a worse prognosis and steroid-dependent NS classification (p = 0.041). The onset-related risk factor "thrombocytosis" appears to be related to a better prognosis (p = 0.03). Conclusion. The relapse risk factors "non-Western ethnicity" and "thrombocytosis" are characterized by worse and better prognosis, respectively. This evidence could support the follow-up of primitive NS in pediatric age.