Objective. Unlike patients with alcoholic hepatitis, patients with acute alcoholic pancreatitis seldom come into the hospital in an intoxicated state. Long-term history of heavy drinking induces increases in the serum pancreatic enzymes and pancreatitis-associated protein profiles during the withdrawal period. The aim of this study was to investigate the role of withdrawal in triggering acute alcoholic pancreatitis by studying the time-course of development of the first symptoms of the first acute alcoholic pancreatitis. Material and methods. One hundred patients (85 M, 15 F, mean age 46, range 18-73 years) with the first acute alcoholic pancreatitis were asked three different questions in an attempt to clarify the same issue: Had you already stopped continuous drinking before the start of the acute abdominal pain that later led to hospitalization? Had you already stopped continuous drinking before you started to experience nausea or vomiting? How many hours after taking the last drop of alcohol did you start to feel pain (0 h, 1 < 6 h, 7-12 h, 13-24 h, 25-48 h, >48 h)? The amount of alcohol consumed was evaluated 1) during the past week and 2) during the past 2 months. The severity of the pancreatitis was assessed by serum C-reactive protein concentration, presence of necrosis, the development of pancreatic complications and the length of stay in hospital and in the intensive care unit. Results. Eighty-five patients were able to respond to the questions. Of these, 69% had developed pain and 91% nausea/vomiting only after they had already stopped continuous drinking. Whereas 29% of the patients developed some symptoms before stopping drinking, the majority of the patients developed symptoms during the first day after cessation (43%) or later (28%), mainly during the second day of cessation of drinking. In both the univariate analysis and the multivariate analysis the timing of the symptoms was dependent on the amount of alcohol consumed during the previous 2 months and in the past week. Conclusions. In the majority of patients with first acute alcoholic pancreatitis, the symptoms begin during the early withdrawal period. The withdrawal period might be more important than previously emphasized in the development of acute alcoholic pancreatitis.