Neurologic symptoms during recovery from spinal anesthesia may reflect residual neuraxial block, but severe pain or persistent motor block can also indicate a compressive neuraxial emergency. A 49-year-old man underwent right knee arthroscopic surgery under spinal anesthesia with 14 mg of 0.5% hyperbaric bupivacaine. The neuraxial procedure was uncomplicated, and perioperative coagulation status was normal. At 225 minutes after intrathecal injection, he developed severe bilateral lower-extremity tightening and twisting pain extending to the buttock/saddle region, with Medical Research Council grade 0 motor strength in bilateral hip, knee, and ankle movements. Gross distal sensation in both feet was documented as present. Because cauda equina syndrome, spinal epidural hematoma, or another acute compressive neuraxial lesion could not be excluded clinically, urgent lumbosacral magnetic resonance imaging was obtained. Magnetic resonance imaging demonstrated left-sided disc extrusion at L4-L5 and L5-S1 with compression of the left L4 and S1 nerve roots; no epidural hematoma, central canal compression, or acute cauda equina compression was reported. The patient was managed conservatively with close observation and symptomatic treatment. Motor function recovered within hours, and at outpatient follow-up 29 days after surgery, no specific abnormality was documented. Severe bilateral leg pain with persistent motor block after spinal anesthesia should prompt structured neurologic reassessment and urgent imaging when compressive neuraxial pathology cannot be excluded clinically.