Hafnia alvei infections are uncommon and occur mainly in adult patients featuring underlying illnesses. Its isolation in pediatric cases is even more unusual. We report a rare case of sepsis combined with urinary tract infection caused by H. alvei in a 39-day-old infant who did not appear to feature any underlying disease. The infant was successfully treated with ceftriaxone over a 14-day period. In this case, we want to remind clinicians that the possibility of an extraintestinal invasive infection such as bacteremia or urinary tract infection caused by H. alvei should be taken into account in young infants who feature no apparent underlying disease.