A 18-month-old boy with stage 4 neuroblastoma needed intensive care because of prerenal acute renal failure related to an intractable watery diarrhoea syndrome occurring 10 months after the diagnosis of the primary tumor. This diarrhoea was in relation with a late hyperproduction of vasoactive intestinal peptide by the relapsing neuroblastoma itself and stopped with intravenous somatostatin administration.