BACKGROUND Hypercapnia and local pressure effects unique to CO(2) base minimally invasive surgery alter renal blood flow. We have demonstrated laparoscopic antireflux surgery to have an additional impact upon hemodynamics (decreased cardiac output), potentially extending known effects upon renal blood flow. METHODS We measured renal blood flow with radioactive microspheres during laparoscopic antireflux surgery in a porcine model. Six pigs were anesthetized, monitoring lines were placed, and microspheres injected five time points associated with a laparoscopic antireflux operation. After euthanasia kidneys were retrieved and fixed, and representative samples counted for radioactivity specific for each of the five time points. RESULTS The greatest reduction in renal blood flow was 36% below baseline (p<0.05). Concurrently, cardiac output had a maximum reduction of 39%. CONCLUSIONS Laparoscopic Nissen fundoplication in this pig model is associated with a significant reduction in renal blood flow, probably related to reduction in cardiac output. Caution is warranted when considering laparoscopic antireflux surgery in patients with a compromised renal blood flow.