The dorsal marginal rabbit ear vein was injected with 0.25 mL of 2.5, 1, or 0.5% sodium morrhuate, 2.5, 1, or 0.5% ethanolamine oleate, hypertonic saline 11.7%, or Sclerodex. Only the vessel injected with 2.5% sodium morrhuate demonstrated clinical and histologic evidence of endosclerosis with microangiopathic recanalization; 2.5% ethanolamine oleate demonstrated partial clinical sclerosis and luminal recanalization histologically. All other evaluated solutions except 0.5% ethanolamine oleate produced immediate clinical and histologic endothelial damage and thrombosis. However, these latter solutions did not produce sufficient endothelial damage to cause endosclerosis. Extravasated red blood cells occurred in vessels injected with 1 and 2.5% ethanolamine oleate and 1 and 2.5% sodium morrhuate at 1 hour and 2 days, but not in vessels injected with sodium morrhuate 0.5%, ethanolamine oleate 0.5%, Sclerodex, or hypertonic saline 11.7%. Hemosiderin discoloration was not apparent clinically. Cutaneous necrosis was not observed with any of the evaluated solutions.