The lumbar zygapophysial joints are a potential cause of back and lower extremity pain. Absolute diagnosis of lumbar zygapophysial joint-mediated pain is based on selective analgesic injections of these joints or their nerve supply. The therapeutic role of zygapophysial joint injections is controversial. This contemporary concepts paper reviews the anatomy, mechanics, pathology, and diagnosis of this condition. A critical review of previous studies assessing the role of diagnostic and potentially therapeutic zygapophysial joint injection procedures is presented. The need for future studies is addressed, and current recommendations for the role of zygapophysial joint injection procedures based on this critical scientific review are provided.