Purpose: This study describes the current etiologies, demographic characteristics, incidence of acute renal insufficiency and correlation between peak creatine kinase (CK) and peak creatinine in hospitalized patients with rhabdomyolysis. Methods: A retrospective chart review of patients with creatine kinase (CK) values greater than 5000 IU/L during a nine month period identified 106 cases of rhabdomyolysis. Results: The most common contributing etiologies were recreational drug and/or alcohol use in 28%, trauma in 23%, compression in 19%, shock in 17%, statin-use in 13%, seizure in 8% and quetiapine-use in 8%. 37% of cases involved multiple etiologies. Renal insufficiency occurred in 49% of cases and modestly but significantly correlated with CK (R2 = 0.41, p < 0.0001). Myoglobinuria and a pre-renal state were associated with renal insufficiency in 49% and 52% of cases, respectively. Conclusions: Rhabdomyolysis should be defined with CK values exceeding 10-25 times the upper limit of normal irrespective of renal function. Using a laboratory marker such as CK can aid diagnosis of rhabdomyolysis and identify adverse drug events.