INTRODUCTION: After failure of nonoperative care for lumbar spinal stenosis, surgical alternatives are generally decompression, fusion, and interspinous devices. In recent years, many interspinous implants have been introduced with good results for appropriately selected patients. The purpose of this study was to compare clinical outcomes of two interspinous devices. METHODS: Data were collected under a Food and Drug Administration regulated trial. Primary selection criteria were stenosis at 1 or 2 levels confirmed by imaging, symptom relief in flexion, failed non‐operative care, and no significant spinal instability. After randomization, 190 patients received the Superion (Vertiflex; Investigational group) and 201 received the X‐STOP (Medtronic; Control group). Outcome measures used included the Zurich Claudication Questionnaire (ZCQ), Oswestry Disability Index (ODI), and visual analog scales (VAS) separately assessing back and leg pain. In both groups, 24 month follow‐up rates were greater than 94%, and 36 mo is near completion. RESULTS: In both groups, ODI, back pain and leg pain VAS symptom severity and physical function scales of the ZCQ, all improved significantly (approximately 50%) as early as 6 weeks after surgery and maintained throughout follow‐up (Figure 1). Reoperation rates were not significantly different in the 2 groups (20.0% Investigational vs. 14.4% Control). Radiographic analysis found no device disassembly or collapse. Both devices increased foraminal height, slightly greater in Control group. But also noted in the Control group was decreased anterior disc space height (“levering effect”). There were no significant differences in occurrence of adverse events in the two groups. DISCUSSION: Both devices produced statistically significant improvement by 6 weeks after surgery which was maintained through 24‐month follow‐up. This prospective study indicates that interspinous devices can produce good outcomes in appropriately selected patients.