Background Acute abdomen is a medical emergency with a wide spectrum of etiologies. Point-of-care ultrasound (POCUS) can help in early identification and management of the causes. The ACUTE–ABDOMEN protocol was created by the authors to aid in the evaluation of acute abdominal pain using a systematic sonographic approach, integrating the same core ultrasound techniques already in use—into one mnemonic. This mnemonic ACUTE means: A: abdominal aortic aneurysm; C: collapsed inferior vena cava; U: ulcer (perforated viscus); T: trauma (free fluid); E: ectopic pregnancy, followed by ABDOMEN which stands: A: appendicitis; B: biliary tract; D: distended bowel loop; O: obstructive uropathy; Men: testicular torsion/Women: ovarian torsion. The article discusses two cases of abdominal pain the diagnosis and management of which were directed and expedited as a result of using the ACUTE–ABDOMEN protocol. The first case was of a 33-year-old male, who presented with a 3-day history of abdominal pain, vomiting and constipation. Physical exam revealed a soft abdomen with generalized tenderness and normal bowel sounds. Laboratory tests were normal. A bedside ultrasound done using the ACUTE–ABDOMEN protocol showed signs of intussusception. This was confirmed by CT-abdomen. The second case was of a 70-year-old female, a known case of diabetes and hypertension, who presented with a 3-hour history of abdominal pain, vomiting and diarrhea. She had a normal physical exam and laboratory studies. Her symptoms mimicking simple gastroenteritis had improved. However, bedside ultrasound, using the ACUTE–ABDOMEN protocol showed localized free fluid with dilated small bowel loop in right lower quadrant with absent peristalsis. A CT abdomen confirmed a diagnosis of intestinal obstruction. These two cases demonstrate that the usefulness of applying POCUS in a systematic method—like the “ACUTE–ABDOMEN” approach—can aid in patient diagnosis and management. Case presentation We are presenting two cases of undifferentiated acute abdomen pain, where ACUTE ABDOMEN sonographic approach was applied and facilitated the accurate patient management and disposition. Conclusion ACUTE ABDOMEN sonographic approach in acute abdomen can play an important role in ruling out critical diagnosis, and can guide emergency physician or any critical care physician in patient management.