We present tow male children who experienced cardiac arrest secondary to unrecognized rhabdomyolysis on the day following an uneventful general anesthetic and recovery room course for adenotonsillectomy. Neither child exhibited hypermetabolism typical of malignant hyperthermia or appeared to have a dystrophinophy, prompting the authors to search for other etiologies of childhood rhabdomyolysis infrequently associated with anesthesia. In this report, we review the heritable metabolic myopathies caused by enzyme deficiencies (enzymopathies) that can lead to life-threatening rhabdomyolysis following certain triggering conditions, and we offer suggestions for avoiding these triggers in the perianesthetic period. We also describe key symptoms an signs that postanesthetic caregivers should be aware of, and briefly comment on follow-up diagnostic studies.