Background: Rhabdomyolysis is a frequent disorder in the pediatric emergency room, and it can result from various acquired and inherited causes. Case presentation: We report the case of a 15-year-old female triathlon athlete with recurrent exertional rhabdomyolysis. The clinical severity alerted for a subjacent cause, and further investigation was taken, leading to the diagnosis of very long-chain acyl-CoA dehydrogenase (VLCAD)deficiency. Conclusion: Exertional rhabdomyolysis may be the first manifestation of a metabolic myopathy, like VLCAD deficiency. VLCAD deficiency has a broad clinical spectrum, and the most common is the late-onset, which presents mainly with episodic symptoms, with predominant muscular involvement and exercise-induced rhabdomyolysis.