Background. Digital radiography has widespread use in endodontics. Determining a correct working length is vital for a proper endodontic therapy. The aim of this study was to compare the accuracy of conventional and digital radiographic techniques for root canal working length determination. Methods. After determining the real working lengths of 50 permanent maxillary central incisors (gold standard), the conventional (E- and F-speed films) and digital (CCD, PSP) images were obtained using the parallel technique. The mean registered working length of each modality was compared with the other and with the gold standard using one-way ANOVA at P<0.05. Results. No significant difference was found between the recorded working length values using the conventional and digital radiographic techniques (P=0.828). Conclusion. Within the limitations of this study, it was concluded that there was no difference between the measurement accuracy of CCD, PSP and conventional imaging techniques in root canal working length determination.