This study highlighted the characteristics and distribution of cracked tooth syndrome (CTS) and the associated factors in adult attendees in the University of Nigeria Teaching Hospital. Three hundred seventy patients aged 18 years to 77 years with CTS-like conditions were included and studied over 12 months. The following information was recorded: suspected tooth and the dental arch, restorative status of the tooth, age and sex of the patient, results of bite test and transillumination, and the pulpal and periapical status of the tooth. CTS was seen most often in the 41 to 50 years age band (36.4%), in molars (63.6%), and in the maxillary arch (51.5%). Also, it was more frequent in men (55.8%). About 82% of CTS occurred in amalgam-restored teeth. All cases had a positive response to the bite test and a normal response to the electric pulp test. Only 10% gave a positive history of masticatory accident as against none with history of bruxism habits. It was concluded that patients with unexplained pain in a vital, amalgam-restored tooth (especially in maxillary molars), with or without a history of a masticatory accident, may have a cracked or fractured tooth.