The operative treatment of unstable pelvic injuries in paediatrics is not frequently indicated. The detailed modes of pelvic ring failure, surgical techniques, fixation choices, and peri-operative difficulties are not well reported. From September 2010 to March 2016, 62 paediatric patients were admitted to an academic level I trauma center with the diagnosis of pelvic ring injury. Of them, 29 (17 males and 12 females) had operative fixation of unstable pelvic injuries. Their average age was 11.7 ± 4.4years. There were six Tile's B injuries and 23 type C injuries. The commonest modes of pelvic ring failure were pubic rami fractures anteriorly and ligamentous sacroiliac joint injuries posteriorly. The iliac apophysis was avulsed in nine patients. Supra-acetabular external fixators were frequently used for anterior fixation while iliosacral IS screws and lateral compression LC screws were commonly used posteriorly. Difficulties were encountered with open reduction and repair of avulsed iliac apophyses in two patients. The IS screws pierced the soft iliac wing in three patients. In two patients with open triradiate cartilage, the purchase of retrograde LC screws was weak due the small sized crescent fragment. The iliac apophysis needs to be repaired following reduction of the displaced hemipelvis. Anterior supra-acetabular external fixation is a good choice in paediatrics even with pubic symphysis diatasis as the pathology is commonly a pubic apophysis avulsion. IS screws might be inserted through plates to prevent piercing the soft iliac wing. Retrograde LC screws should be avoided in young children.