BACKGROUND DATA: Neonatal primary peritonitis (or autonomic bacterial peritonitis) is a diffuse peritoneal inflammation without any obvious visceral cause. It is a disease rarely described during the neonatal period. OBJECTIVE: The aim of the current study was to make the surgical community aware of it, in an attempt to help a prompt diagnose and to avoid any unnecessary surgery in patients admitted in Neonatal Intensive Care Unit (NICU). MATERIALS AND METHODS: It concerns the description of 7 cases of newborns affected by primary peritonitis during their hospitalization in the NICU, underlining their signs and symptoms along with all additional paraclinical tests and the final outcome. RESULTS: Primary peritonitis was identified in 7 neonates (5 females and 2 males). Despite the severity of their symptoms (e.g. abdominal sensibility, a long standing ileus etc.) none of them had sustained any surgery and the mortality was nil. CONCLUSIONS: Neonatal primary peritonitis should always be taken into account in such circumstances. The final outcome, despite the initial clinical severity, is favorable with the appropriate conservative therapy.