The viability of the rabbit epigastric flap was investigated after a period of cold ischemia of 3, 4, or 5 days. Groups of flaps were either perfused with Ross's solution before ischemia (early perfusion), after ischemia (late perfusion), or not at all (control). Significantly more flap necrosis was formed at exploration 7 days after revascularization in the early perfusion group than in the control group (p less than 0.01). Late perfusion was not significantly detrimental to flap survival as compared with cold storage alone (0.1 less than p less than 0.5). It is concluded that early perfusion is detrimental to the ultimate fate of the cold ischemic flap, whereas late perfusion offers no advantage over cold storage alone.