Cis and trans isomers of 1,2-diphenyl-1,2,3,4-tetrahydronaphthalenes, novel processes for the preparation thereof, and novel intermediates are disclosed herein. The novel 1,2-diphenyl-1,2,3,4-tetrahydronaphthalenes have utility as antifertility estrogenic, anti-estrogenic, anti-spermatogenic, cholesterol lowering and lipid normalizing agents.