Spondylolysis and spondylolisthesis are common causes of low back pain in children and adolescents. Disc space infection is less common, but is another cause of severe back pain in this population. The combination of both processes in the same segment is rare. This case report is of a 13-year-old patient with isthmic lumbosacral spondylolisthesis and disc space infection at the same level. A patient who presented with severe low back pain and a radiological picture of isthmic slip with end plate irregularities and anterior bridging osteophyte was diagnosed with disc space infection at the slip level. He was managed with intravenous antibiotics for 6 weeks, followed by oral medication for an additional 2 weeks. At follow-up 28 weeks later, a spontaneous radiological fusion at the slip level was noted with complete relief of his symptoms. The patient was able to resume sports activities. In conclusion, isthmic spondylolisthesis and disc space height infection might coexist. Nonoperative treatment will usually result in spontaneous fusion and the complete relief of symptoms.