Inferior alveolar nerve block (IANB) is the main technique for anaesthetization in the mandible. Profound inferior alveolar nerve block (IANB) aesthesia remains difficult to achieve at all cases. Multiple causes of failure or incomplete anesthesia were reported. To assess IANB failure rate among dental students and instructors, the susceptible causes of failure, and how it is overcome. In addition to investigate the awareness of alternative techniques of IANB and the rate of IANB-related complications. A questionnaire containing twenty questions was distributed for 300 of dental students and interns and also for 100 of instructors at the vision colleges /Jeddah -Riyadh/Saudi Arabia. It included demographic questions, questions on IANB failure rate and causes, how the failure is usually overcome, awareness of different alternative anaesthetic techniques and the most common encountered complications. 356 participants were involved in the study. Most of surveyed sample (91.3%) had experienced IANB failure. The most commonly reported causes of failure were unclear landmarks (46.1%) and anatomical variations (38.5%). The most common alternative technique used was intraligamentary injection (49.4%). The most common reported complications according to our respondents were facial paralysis (17.1%) and trismus (16.3%). More training of students on IANB injection is needed. In addition alternatives to IANB, such as the Gow-Gates and Akinosi techniques should be activated and emphasized, theoretically and clinically, in the anesthesia courses of the dental curriculum.