Mirizzi syndrome occurs in up to 6% of patients with cholecystolithiasis. It is generally caused by external compression of the common hepatic duct by a gallstone impacted in the neck of the gallbladder or the cystic duct, which can lead to fistulisation. The aim of this review was to highlight the proposed classifications for Mirizzi syndrome (MS) and to provide an update on modern approaches to the diagnosis of this disease. We conducted research on various internet databases and the total number of records was 993, but after a gradual process of elimination our final review consisted of 21 articles. According to the literature, the Cesendes classification is the most commonly used, but many new suggestions have appeared. Our review shows that the ultrasonography (US) is the most frequently used method of initial diagnosis, despite still having only average sensitivity. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) are good methods and are similarly effective, but only the latter can be simultaneously therapeutic. Some modern methods show very high sensitivity, but are not so commonly administered. Mirizzi syndrome is still a diagnostic challenge, despite the advancement of the available tools. Preoperative diagnosis is crucial to avoid complications during treatment. New research may bring a unification of classifications and diagnostic algorithms.