Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is one of a number of well described hereditary periodic febrile syndromes. We report a case in an infant, with a strong family history of this disorder, who presented on day-of-life 4 with high fever, irritability, diarrhea, lethargy, and raised acute phase reactants. An extensive work-up, including a full sepsis evaluation, proved negative. Symptoms resolved spontaneously. Representation with similar symptoms at 7 months of age prompted successful diagnosis after full evaluation. Subsequent genetic mutation analysis has proven positive for the T50M mutation in exon 2 of the TNFRSF1A gene. To our knowledge, this is the youngest reported age of presentation of this rare autoinflammatory disorder which should be considered even at such a young age.