Introduction Mobile health (mHealth) is the use of mobile communication devices such as smartphones, wireless patient monitoring devices and tablet computers to deliver health services. Paediatric surgery patient care could potentially benefit from these technologies. This systematic review summarises the current literature on the use of mHealth for postoperative care after children’s surgery. Methods Seven databases were searched by a senior medical librarian. Studies were included if they reported the use of mHealth systems for postoperative care for children <18 years old. Data extraction and risk of bias assessment were performed in duplicate. Results A total of 18 studies were included after screening. mHealth use was varied and included appointment or medication reminders, postoperative monitoring and postoperative instruction delivery. mHealth systems included texting systems and mobile applications, and were implemented for a wide range of surgical conditions and countries. Discussion Studies showed that mHealth systems can increase the postoperative follow-up appointment attendance rate ( p < 0.001), decrease the rate of postoperative complications and returns to the emergency department and reliably monitor postoperative pain. mHealth systems were generally appreciated by patients. Most non-randomised and randomised studies had many methodological problems, including lack of appropriate control groups, lack of blinding and a tendency to devote more time to the care of the intervention group. mHealth systems have the potential to improve postoperative care, but the lack of high-quality research evaluating their impact calls for further studies exploring evidence-based mHealth implementation.