An accurate diagnosis is essential for making treatment decisions in dentistry. However, little research is available as to which tests are done routinely and how commonly they are performed. The purpose of this study was to investigate diagnostic methods and equipment used by general dentists in private practice in Perth. The study involved a retrospective audit of 30 patient records from seven individual general dentists working in private practices in the Perth Metropolitan area. De-identification of patient records was done prior to the researchers' visit. Radiographs were the most commonly used diagnostic tool. Percussion was also commonly employed, followed by cold pulp testing and mobility. The most commonly used tests were radiographs, percussion, periodontal probing and visual examination. The frequency of these tests differed depending on whether the patient presented with or without pain, with percussion and cold tests used more frequently when the patient presented with pain.