Skeletal muscle may release creatine kinase (CK) during a malignant hyperthermia (MH) episode; however, muscle damaged during surgery may also release CK. This study examined the overlap between peak plasma CK levels in patients suspected of having had a MH episode (data obtained from North American MH Registry) and previously published CK changes occurring after common surgeries. For patients who were subsequently proven to be MH positive by muscle biopsy, there was considerable overlap. This was most significant with surgeries having substantial tissue damage, such as major vascular surgery and abdominal surgery. Overlap was much less with minimally invasive surgery, such as cystoscopy. Approximately 30% of MH positive patients treated with dantrolene had peak CK in the range of most surgical procedures, and approximately 50% of MH positive patients not given succinylcholine had peak CK similar to those of most surgical procedures. Dantrolene did not significantly alter peak CK in MH positive patients; however, succinylcholine was associated with significantly higher peak CK. These data suggest that patients who have had an acute MH episode during a surgical procedure may have peak CK values within the range of CK values expected from the procedure itself.