The introduction and development of nickel-titanium rotary instruments are undoubtedly improving the quality of Endodontics treatment. The study aimed to assess, dentist knowledge and practice of using NiTi Rotary instrumentation for the root canal treatment. Also to assess their level of success and failure when using rotary files according to the year of experience and their ability to manage procedural errors in comparison to hand instrumentations. A descriptive cross-sectional study among 167 (Endodontists and general practitioners) working in private clinics within Khartoum City, Sudan. A self-administered questionnaire including questions about the uses of NiTi, failures during treatment, and how they managed to overcome. Comparison between variables by Chi-squire test with the level of significance set at a P-value of ≤0.05. The result showed that NiTi rotary files for root canal preparation were used by 72%, with a failure rate of RCTs among 63%, and the majority 80% managed to overcome procedural errors. Crown down as a preparation technique was used by 99.2%. The most commonly used rotary system files were pro taper (83.3%). The rate of file breakage is directly related to their repeated use, before discarding them and those who managed to treat failure were those with more years of experience and endodontists rather than the general practitioners. In conclusion, the majority of dentists working within private clinics in Khartoum city, use NiTi rotary system for RCT, and years of experience was the major factor in managing the RCT failures.