A 10-year-old boy presented with severe left lower leg pain, uncontrolled with increasing analgesia after appendicectomy. A diagnosis of acute compartment syndrome was made after a delayed referral to the orthopaedic service. The patient subsequently underwent an emergency fasciotomy and made a good functional recovery. To the best of our knowledge this is the first reported case of paediatric lower leg compartment syndrome after appendicectomy in the literature. The case report serves to highlight the importance of maintaining a high index of suspicion for compartment syndrome.