The authors present the case of a 51-year-old woman with no history of surgical or traumatic injury or accident, who presented with right hypochondrium and epigastric discomfort, malaise, nausea, loss of appetite and episodes of dark urine and greenish stools. Initial laboratory work-up revealed elevated inflammatory markers including leucocytosis with left shift and C-reactive protein, and a slight elevation of gamma-glutamyltransferase and alkaline phosphatase, with no other significant alterations. Computed tomography (CT) showed intrathoracic acute cholecystitis with a large diaphragmatic hernia. A literature search revealed only one other case of acute cholecystitis complicated by intrathoracic gallbladder due to a non-traumatic diaphragmatic hernia. Symptoms are uncharacteristic and the absence of pain or fever, explained by the altered location of the gallbladder, makes the diagnosis a challenge.