This retrospective study of 118 teeth receiving root canal treatment was conducted to determine the frequence and complications of delayed root canal treatment. Teeth were categorised into prompt treatment group and delayed treatment group according to the length time of treatment; prompt treatment group was defined as a group where root canal treatment was achieved within a period of 4 months or less, and delayed treatments group, a group where period of treatment was greater than 4 months or where canals were never obturated. Two types of complications were studied: postobturation pain and fracture involving tooth extration. The results of this study have shown that 34.5% of treatments were delayed. In this group we found also a higher rate of fractures involving tooth extraction, but the difference was not significant. The results have also shown that disappearance of pain was the essential factors in the frequence of delayed treatment, but the dental chair breakdown had some responsability. As well as in the two groups, the first reason of extractions was fracture and not pain. These results emphasize the necessity of focusing the patient's motivation on the risk of losing the tooth.