BackgroundSurgical smoke during operation is a well-known health hazard for medical staff. This study aimed to investigate the dynamics of surgical smoke during open surgery or laparoscopic surgery for colorectal disease.MethodsThis study quantitated particulate matter (PM) counts as part of surgical smoke in 31 consecutive patients who underwent colectomy at the Niigata City General Hospital using a laser particle counter. Particles were graded by size as ≤ 2.5 μm PM (PM2.5) or > 2.5 μm PM (large PM). Operative procedures were categorized as either open surgery (n = 14) or laparoscopic surgery (n = 17).ResultsThe median patient age was 72 (range 41–89) years and 58.1% were male. The total PM2.5, PM2.5 per hour, and maximum PM2.5 per minute counts during operation were significantly higher in open surgery than in laparoscopic surgery (P = 0.001, P < 0.001, and P = 0.029, respectively). Large PM counts (total, per hour, and maximum per minute) were also higher in the open surgery group than in the laparoscopic surgery group. The maximum PM2.5 concentration recorded was 38.6 µm/m3, which is considered “unhealthy for sensitive groups” according to the U.S. Environment Protection Agency air quality index standards, if it was a 24-h period mean value.ConclusionExposure to surgical smoke is lower during laparoscopic surgery than during open surgery for colorectal diseases.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00464-021-08394-1.