Inferior alveolar nerve block anesthesia is one of the most common procedures in dental clinic. Although it is well known as safe procedure, complications always can be occurred. Ocular complications such as diplopia, loss of vision, opthalmoplegia are very rare, but once it happens, dentist and patient can be embarrassed and rapport will be decreased between them. We experienced one diplopia case after inferior alveolar nerve block anesthesia and treated without any further complication. We report this case and describe the cause, diagnosis, and treatment objectives of diplopia caused by inferior alveolar nerve block anesthesia.