Objective: Comparison between bovine-derived demineralized bone matrix (DMBM) and iliac crest graft over long term for secondary alveolar bone grafting (SABG) in patients with unilateral cleft lip and palate (UCLP) in terms of radiological and clinical outcomes. Design: Prospective, randomized, parallel groups, double-blind, controlled trial. Setting: Unit of Oral and Maxillofacial Surgery, Oral Health Science Centre, Postgraduate Institute of Medical Education & Research, Chandigarh. Participants: Twenty patients with UCLP. Interventions: Patients were allocated into group I (Iliac crest bone graft) and group II (DMBM) for SABG. Outcomes were assessed at 2 weeks, 6 months, and then after mean follow-up period of 63 months. Outcomes Measures: Volumetric analysis of the grafted bone in the alveolar cleft site was done through cone beam computed tomography using Cavalieri principle and modified assessment tool. Clinical assessment was performed in terms of pain, swelling, duration of hospital stay, cost of surgery, alar base symmetry, and donor site morbidity associated with iliac crest harvesting. Results: Volumetric analysis through Cavalieri principle revealed comparable bone uptake at follow-up of 6 months between group I (70%) and group II (69%). Modified assessment tool showed no significant difference between horizontal and vertical bone scores over short- and long-term follow-up. In group II, there was higher cost of surgery, but no donor site morbidity unlike group I. Conclusions: Demineralized bone matrix proved analogous to iliac crest bone graft as per volumetric analysis over shorter period. However, although statistically insignificant, net bone volume achieved was lower than the iliac crest graft at longer follow-up.