Mietek was born in Poland in 1938. In 1962 he studied at the University of Arts in Warsaw, Poland, where from 1963 to 1974 he was an associate professor of art. Arrived in Venezuela in 1974 and became a Venezuelan citizen in 1980. He teaches at the Design Institute Neumann-Ince from 1967 to 1990. he also teaches at the Universidad Simón Rodríguez, Caracas. In 1975 wins First Prize at the Salon of Drawing and Engraving, Universidad de Los Andes, Merida, Venezuela.