A 5-year clinical follow-up study was conducted to determine the longevity of originally acceptable results for internal bleaching. The "walking internal bleaching" method is an acceptable technique of lightening discolored anterior teeth to provide an esthetically pleasing match with adjacent teeth. This follow-up study revealed a success rate of 79% for all indications after 5 years. If the indication is limited to one palatal endodontic opening, the total success rate can reach 91%. However, a 98% success rate is common when subjective evaluation of patients is considered. The results clearly indicated that internal bleaching provides long-term success for treatment of discolored nonvital anterior teeth over a period of years and does not have any detrimental effect on dental hard tissue. In ideal cases, if the procedure is performed precisely, the success rate can exceed 90% after five years.