A transoesophageal Doppler cardiac output monitor was used to study the cardiovascular changes occurring during laparoscopic cholecystectomy in patients without (group A) or with (group B) a history of cardiovascular disease, i.e. hypertension, ischaemic heart disease or heart failure. Insufflation of the abdomen with carbon dioxide caused significant (P<0.01) falls in mean cardiac index (17.9% in group A, 25.1% in group B) and mean stroke volume index (15.3% in group A, 21.2% in group B). Simultaneously, there was a significant (P<0.05) increase in mean systolic blood pressure (19.4%) in group A. There were no other differences in the cardiovascular responses of the two groups. There was no correlation between systolic blood pressure and either cardiac index or stroke volume index. No significant complications or morbidity were associated with the use of the transoesophageal Doppler monitor. We conclude that the cardiovascular changes associated with insufflation are neither predictable by clinical assessment nor adequately determined by routine monitoring. We recommend the transoesophageal Doppler monitor for use in this situation.