Temporomandibular joint disorders (TMJD) include temporomandibular joint dysfunction and bruxism. Sacroiliac joint dysfunction (SJD) is a frequent cause of non-discogenic low back pain. Studies suggest a relationship between TMJD and SJD; however, the link remains unclear. Neural therapy (NT) utilises local anaesthetic injections to treat pain by normalising a dysfunctional autonomic nervous system held responsible for initiating or propagating chronic pain. A 31-year-old female presented with a 1-year history of mechanical left-sided low back pain and sleep bruxism. Examination revealed crepitation of the left TMJ and a trigger point in the masseter muscle. Range of motion of the spine and hip joints were normal, Patrick and Geanslen tests were positive on the left side. Spine and standing flexion tests were also positive. Magnetic resonance imaging of the lumbar spine and sacroiliac joints were normal. A diagnosis of SJD was made, and the patient was treated using NT. Injections of lidocaine 0.5% to the left TMJ, the masseter muscle and intradermal segmental injections at the level of C4 were administered. The patient's back pain and TMJ tenderness reduced and continued so throughout the 3-month follow-up period. SJD may be related to TMJD, and NT may be used in its treatment.