The reaction of 3-[acyl(ethoxycarbonyl)]methylidene-, 3-diethoxycarbonylmethylidene-, and 3-diacylmethylidene-1,2-diferrocenylcyclopropenes with hydrazine at 80-85°C afforded 3,4,5,6-tetrasubstituted 5-acyl(-ethoxycarbonyl)pyridazines (3a-f) in 65-70 % yield. The structures of the obtained ferrocenylpyridazines were determined by IR and 1 H and 13 C