Reactions of various 3-aroylmethylene-indol-2-ones with hydrazine and phenylhydrazine under exactly similar conditions have been carried out. The reaction with phenylhydrazine has not been investigated earlier. It was found that although the reaction with hydrazine hydrate afforded a spiro derivative viz., spiro[3H-indole-3,3'-(3H)pyrazol]-2(1H)-one, that with phenylhydrazine yielded simply a hydrazone derivative. Representative spiro compounds have been screened for antifertility activity but none was found active at a dose of 10 mg/kg in adult female rats.