Appendicitis rarely presents with an left lower abdominal pain especially when the intestine is non-rotated or malrotated. Its diagnosis becomes quite troublesome to clinicians and delays prompt intervention. Non-rotation is the most common type of intestinal malrotation. Here, we present a case of a 40-year-old female with previously undiagnosed intestinal non-rotation with left lower abdominal pain and features of localised peritonitis. Abdominal ultrasonography and multidetector computerised tomography showed left-sided appendicitis with intestinal non-rotation. Diagnostic laparoscopy followed by explorative laparotomy and appendectomy was performed. Clinicians and surgeons are usually trained to diagnose and operate on right-sided appendix, thus, diagnosing and promptly intervening on left-sided appendicitis is quite challenging. Left-sided appendicitis must be kept in mind if a patient presents with left lower abdominal pain. Timely radiological scans like ultrasonography and computerised tomography scans help in prompt diagnosis in these cases.