The oldest son of a family of manufacturers that had owned and run a steelworks in Spessart for four generations, he studied Engineering in Nürnberg.
Within the scope of the Gestapo clampdown on the Anthroposophists and anthroposophical institutions on 9 June 1941, Alfred Rexroth was interrogated, his house searched and his library with a large number of anthroposophical books seized.