 By 1943, he had created the "Venezolana de Cementos", the largest supplier of cement in the country.Also, in the following years he conformed "Protinal", dedicated to the production of animal feed, "Venezolana de Pinturas" and "Venezolana de Pulpa y Papel".His business organization, "El Grupo Mendoza" became the largest industrial conglomerate in the 1970s encompassing everything from cement, construction, manufacturing, heavy machinery, paint, paper mills, animal feed, banking, and insurance to ownership of General Motors of Venezuela..

Mendoza's grandson by his daughter Antonieta Mendoza is Leopoldo López Mendoza, a leading opposition leader in Venezuela and former Mayor of Chacao.