We report a 48-year-old male admitted to hospital due to a severe alcoholic pancreatitis. At four weeks of evolution of the acute episode, an abdominal CAT scan showed a fluid collection of 20 cm diameter located in the pancreatic tail and 2 small collections in the head. The patient received several antimicrobials and during the seventh week of evolution, while receiving vancomycin, presented fever. A fine needle aspiration of the cyst revealed the presence of Haemophilus parainfluenzae biotype VIII. The patient was treated with amoxicillin-clavulanic acid and a laparoscopic cysto-gastrostomy, with a good clinical response.