Aim: The aim of the present study was to assess the pain relief, Visual Analogue Scale (VAS), and Oswestry disability index (ODI) in patients operated for moderate lumbar instability with interspinous distraction and stabilization.Methods: This was a hospital based prospective study. The Institutional Ethical Committee approved it. The study population consisted of 50 indoor patients with a history of low back pain with or without pain radiating down to lower limbs and operated with Synthes ‘In-Space’ interspinous distraction and stabilization and who also met the inclusion and exclusion criteria.Results: 60% were male. Most of patients i.e. 23(46%). were from age group 41 to 60 years. Instability with prolapsed intervertebral disc (PIVD) i.e.20 (40%) was more common than only instability or instability with lumbar canal stenosis. Majority of surgical procedures done was IDSS (26 i.e.52%) alone followed by IDSS with discectomy. In most cases the implant was placed at L-L5 level (i.e. 70%). 12 mm (i.e. 37.04%) sized implant was mostly used in the patients.Conclusion: We have found it to stabilize the spine in moderate instability. IDSS for lateral recess stenosis was performed with micro techniques using micro lumbar approach and is also minimally invasive. The post-operative morbidity is the least and quick mobilization within hours of the surgery and quick discharge from the hospital gives added confidence to the patient. Using the In-space interspinous distraction and stabilization alone or in combination with fixation and fusion methods in the treatment of moderate lumbar instability and lumbar degenerative disease is a simple, safe and effective treatment, with a good curative effect observed in the initial follow up. The results were statistically significant at 6 months.