A new autoperfusion preparation was used to preserve six major organs simultaneously. In 7 Yorkshire white swine, the heart and lungs were separated and removed with the liver, pancreas, duodenum, and both kidneys en bloc while they were self-perfused. Fresh blood, glucose, electrolytes, heparin sodium, methylprednisolone, and a fat emulsion (Soyacal) were infused through the portal vein. No inotropic drugs were necessary. The organs survived for 18 to 37 hours (average survival, 24.6 +/- 2.7 hours [+/- standard error of the mean]). Aortic systolic pressure ranged from 78.5 +/- 5.5 to 98.7 +/- 11.8 mm Hg. Arterial oxygen tension ranged from 206 +/- 23 to 266 +/- 15 mm Hg and arterial carbon dioxide tension, from 20.1 +/- 2.7 to 32.1 +/- 4.9 mm Hg. Blood lactic acid levels decreased from 8.75 +/- 2.06 to 5.50 +/- 2.45 mmol/L at 24 hours. Urine output ranged from 25 to 82 mL/h. Blood urea nitrogen levels decreased from 9.17 +/- 0.59 to 4.67 +/- 1.08 mg/dL. Blood creatinine levels decreased from 1.34 +/- 0.10 to 0.57 +/- 0.22 mg/dL. Serum glutamicoxaloacetic transaminase levels increased from 73.4 +/- 26.3 to 194 +/- 179.5 U/L and serum glutamic-pyruvic transaminase levels, from 44.8 +/- 5.7 to 91 +/- 66.4 U/L. Red blood cell count ranged from 6.94 +/- 0.58 to 13.23 +/- 2.30 x 10(6)/microliters. Lung wet/dry weight ratios changed from 5.79 +/- 0.17 at the beginning to 6.25 +/- 0.16 at 24 hours. The technique for simultaneous multiorgan preservation presented here is simple, effective, and highly reproducible. This study appears to have produced one of the longest average survival times for autoperfusion.