Introduction: Zoledronic acid or zoledronate is a potent bisphosphonate that recently has been used in children with osteoporosis and osteogenesis imperfecta (OI), so it could be an option in the treatment of children with this terrible disease that virtually condemns them to a life of pain and prostration. The aim of this study was to evaluate the clinical and biochemical conditions of pediatric patients with OI before and after treatment with zoledronate. Results: We included 14 patients, median age six years (6 months to 14 years), eight (57.1%) males and six (42.9%) females, weight 19 kg (5.8-45 kg). According to the type of OI, six (42.9%) were type I, six (42.9%) type III, and two (14.2%) type IV. The functional score (Bleck) previous to treatment was 4 (1-9) and 6 (2-9) after treatment (p = 0.001). Pain intensity prior to zoledronate was 2 (1-9) and 0 (0-2) after (p = 0.008). Previous fractures five (1-15) and post-treatment one (0-2) (p = 0.001). There were no significant differences in calcium, phosphorus, alkaline phosphatase, and parathyroid hormone. Conclusions: Zoledronic acid decreases the number of bone fractures and pain in children with osteogenesis imperfecta and improves functional status. The most common side effects were fever and bone pain within five days after the infusion, which disappear with paracetamol. No adverse long-term effects such as hypocalcemia or hypoparathyroidism were reported.