Haemodynamic alterations occur consistently with laparoscopic surgery in humans. These haemodynamic changes have never been reproduced in an animal model without additional potentiating factors. As these alterations may be deleterious in some patients and as the cause is only partly understood, we have used an animal model to study these changes. Pneumoperitoneum with intraperitoneal pressures of up to 15 mm Hg were produced in pigs, in the same way as for laparoscopic surgery in humans. Arterial pressure, cardiac output, pulmonary arterial pressure and systemic arterial resistance were assessed at baseline and after pneumoperitoneum had been produced. Intraperitoneal pressures of up to 15 mm Hg were not associated with consistent circulatory changes and we conclude that haemodynamic changes associated with laparoscopic surgery are dependent on species.