The authors report the case of a 58-year-old man who presented with a cervicothoracolumbosacral spinal subdural abscess about a month after receiving an epidural steroid injection for management of low-back pain due to L5-S1 disc herniation. Although he presented with symptoms concerning for a spinal etiology, the subdural empyema was not evident on the initial MRI study and was observed on imaging 5 days later. This patient was successfully managed with surgical intervention and antibiotic treatment, and he is doing well more than 21 months after the operation. It is possible that a prior history of disc herniation or other spinal abnormality may increase a patient's risk of developing spinal subdural empyema. This case illustrates the risk of infection following spinal epidural steroid injections and the importance of early recognition and intervention to successfully treat an extensive subdural abscess.