Abstract Background Intravenous zoledronate, has been indicated for the treatment of Osteogenesis imperfecta (OI). It is a heritable disorder that causes bone fragility. The purpose of this study was to evaluate its effect on functional mobility scale and scoliosis degree on children with OI. Methods and Results This observational study was conducted on 28 OI patients (12 boys & 16 girls) aged 1.3-7.15years. All parameters were evaluated at Pediatric Endocrinology clinic, Children’s Hospital, Ain Shams University. Treatment was started with zoledronate dose 0.05 mg/kg every 6 months. Children less than 3 years of age received intravenous Zoledronate at a dose of 0.025 mg/kg per dose every 6 months with a maximum dose of 2 mg, while children above 3 years old received 0.05 mg/kg/dose every 6 months with a maximum dose of 4 mg. FMS and scoliosis degree using cobb anglewere evaluated before and after zoledronate therapy. Patients showed highly significant improvement in FMS. Patients with mild and moderate degree of scoliosis showed a non significant improvement in the degree of scoliosis while patients with severe scoliosis didn’t show any statistically significant difference. Conclusion Our study showed that intravenous zoledronate treatment, given once every 6 months, is an effective mode of treatment in OI children. It was associated with improvement in FMS. Longer follow-up is necessary to monitor the effect of treatment on degree of scoliosis by cobb angle.