BACKGROUND: There are no guidelines for the management of patients with cryoglobulins during cardiopulmonary bypass (CPB) necessitating core hypothermia. OBJECTIVE: To evaluate a simple, pragmatic protocol of in vitro temperature-dependent cryoprecipitation of serum in patients with cryoglobulinemia before elective cardiac surgery with CPB. METHODS: A 44-year-old female patient was known for chronic hepatitis C and type III cryoglobulinemia. Elective surgery was planned for an aortic arch aneurysm. A differential serum cryoprecipitation profile was established in vitro prior to surgery. RESULTS: Whereas, at temperatures < or = 15 degrees C, cryoglobulin levels were > or = 0.112 g/L (normal value < 0.05 g/L), at 20 degrees C and above, the precipitate was < or = 0.016 g/L. Accordingly, surgery was performed without any cryoglobulin-related complications at an extracorporeal circulation temperature of 22-24 degrees C, to minimise the risk of cryoprecipitation. CONCLUSION: In elective cases of surgery with CPB and hypothermia, temperature-dependent differential serum cryoprecipitation profile may be an easy and efficient way to assess a safe peroperative level of temperature to avoid complications due to cryoglobulins, without enhancing the patient's tissue ischemia risks.