Objective: Cholelithiasis represents a very frequent health problem with higher prevalence in developed countries. The aim of this chapter is to underline, also by submitting our surgical experience, some diagnostic deceptions and the timing of treatment. Methods: The presentation of 42 patients admitted in our institution (September 2012/September 2014) with the diagnosis of acute pancreatitis allows to identify two different clinical forms of acute biliary pancreatitis: the pancreatic pattern and biliary pattern. Moreover, the evaluation of another 42 patients observed in our institution (September 2014/September 2016) with acute cholecystitis should show our treatment program. Also, we added the analysis of our previous research, regarding acute cholecystitis, already published: difficult cholecystectomy, antegrade dissection in laparoscopic cholecystectomy, postoperative morbidity, laparoscopic approach in cirrhotics, finally the robotic experience. Results: Clinical features, laboratory, and imaging exams should identify, into acute biliary pancreatitis, two clinical forms as biliary pattern and pancreatic pattern for different therapeutic approach. The treatment chosen for acute cholecystitis is early laparoscopic cholecystectomy within 24–72 hours. Severe, complicated acute cholecystitis can require urgent surgical intervention. Conclusion: Acute cholecystitis encompasses clinical forms with various degree of severity and several clinical courses. The treatment is focused on early cholecystectomy with various and different management strategies, suitable to the specific pathological conditions.