The article presents data on the analysis of the flow rate and the level of bile amylase in 56 patients with biliary acute pancreatitis of varying severity (according to rapid assessment) and cholecystolithiasis operated on urgent indications. Bile flow of more than 500 mL per day corresponds to mild severity (R = 4,000; CI = 0.956–10.880; p 0.05) and is rare in severe cases of the disease (R = 0.133; CI = 0.022–0.515; p 0.05). Bile flow less than 100 mL per day is characteristic only for severe course (R = 0.133; CI = 0.467–27.735; p 0.05). Differences in the level of bile alpha-amylase are statistically significant between mild and severe course of biliary acute pancreatitis (p = 0.000011) and are not significant between moderate and severe course of the disease (p = 0.146275). For severe and moderate disease, the decrease in alpha-amylase indicators occurred stepwise, with significant differences on days 2 and 5 after surgery. Indicators of bile flow rate and of alpha-amylase level can be prognostic criteria for the severity of biliary acute pancreatitis.