BACKGROUND: To adequately perform peritonectomy, the use of an electrocautery device at a high voltage is recommended. The aim of this study was to analyse the amount of airborne and ultrafine particles (UFP) generated during peritonectomy and to compare this with standard colon and rectal cancer surgery (CRC). METHOD: UFP was measured approximately 2-3cm from the breathing area of the surgeon (personal sampling) and 3m from where the electrocautery smoke was generated (stationary sampling) from 14 consecutive peritonectomy procedures and 11 standard CRC resections. The sampling was by P-Trak UFP counter that has the capacity to detect particle size ranging from 0.02 to 1mum. RESULTS: The cumulative level of UFP of personal sampling in the peritonectomy group was higher (9.3x10(6)particle/ml/h (pt/ml/h)) than in the control group (4.8x10(5)pt/ml/h). A higher cumulative level of UFP in stationary sampling was observed in the PC group (2.6x10(6) pt/ml/h) than in the control group (3.9x10(4)pt/ml/h). CONCLUSION: Peritonectomy procedure with high voltage electrocautery generates elevated levels of UFP than standard CRC surgery does. The level of UFP produced by a peritonectomy is comparable to cigarette smoking. More efficient smoke evacuator systems are needed in order to reduce the levels of UFP generated during electrocautery surgery.