Trigger point injections (TPI) are commonly used therapeutic intervention to relieve myofascial pain. However, TPIs sometimes cause infection that requires surgical intervention, such as incision and drainage. Since TPIs are commonly applied to the posterior neck muscles for relieving cervical pain or chronic headache, head and neck surgeons can encounter patient with abscess of posterior neck muscle caused by TPIs, which occurred in unfamiliar anatomical location. There are several points to be cautious in draining abscess of posterior neck due to crucial structures nearby. We reported our experience of surgical drainage of abscesses of the splenius capitis and levator scapulae caused by TPIs with a literature review focusing on anatomical considerations on surgical drainage of abscess.