Cryopreservation of whole organs would not only be advantageous for experimental biology but also for transplantation surgery. The objective of this study was to evaluate the feasibility of cryopreserving swine uterus as an experimental model of cryopreservation affecting a whole visceral muscle organ. Organs were frozen slowly (0.2 degrees C/min) after arterial perfusion with 10% dimethyl sulfoxide solution for 10 min and equilibration in this solution for 30 min. Viability of the organs was tested by biochemical parameters, LIVE/DEAD fluorescent staining and capability for contraction in a perfusion system. Ten fresh and ten cryopreserved uteri showed living cells in the LIVE/DEAD assay, and were viable for at least 7 h as shown by their ability to produce rhythmic contractions after oxytocin administration. This is the first report known to us on successful cryopreservation of a whole swine uterus to demonstrate that perfusion with a cryoprotectant and slow freezing provides a promising method for cryopreserving whole organs, and may encourage further studies with other cryoprotective agents and freezing protocols as well as other organs.