A 15-year-old female adolescent with a medical history of recurrent urinary tract infections and grade 1 left-sided vesicoureteral reflux presented to the emergency room with abdominal and back pain. Labs revealed a haemoglobin A1c (HbA1c) of 9.1% and a random blood glucose of 200 mg/dL, consistent with new-onset diabetes mellitus. Nasopharyngeal COVID-19 PCR test returned positive. A CT scan of the abdomen and pelvis revealed bilateral attenuation of the kidneys and air in the bladder, which was confirmed by pelvic ultrasound. Gas subsequently resolved 2 days later after treatment with antibiotics, and a diagnosis of emphysematous cystitis was made. Emphysematous cystitis in the paediatric population is an extremely rare condition with four cases reported in the literature. Furthermore, there has been a reported association between COVID-19, cystitis and non-typical course of urinary symptoms. Local inflammation obstructing transportation of formed gas is one of the proposed mechanisms underlying emphysematous cystitis, and so COVID-19 may be yet another predisposing factor.