This paper investigates the Successive Mean Quantization Transform (SMQT) for enhancement of dental X-ray images. The aim is to provide an automatic tool for enhancing the dental X-rays that would aid an interpreter, who is typically a specialist in dentistry. The evaluation is performed based on a subjective test by a clinical expert/endodontist who has vast experience in dental X-ray analysis and diagnosis. Based on the subjective test for a number of dental images, this SMQT based enhancement method is found to provide a useful tool for enhancing the diagnostic value of dental X-ray images. © 2005 IEEE.