The son of a textile and garment factory owner, Narducci practically grew up in the clothing industry. From a very young age he showed in interest in fashion and design which was nurtured by his family. He attended the Rhode Island School of Design and after graduating in 1960 he moved to New York City to start his career. He began submitting fashion editorials to Vogue, Harper's Bazaar and WWD as well as other top women's wear magazines and was soon acclaimed as one of the top five designers in America. Over the years, Leo's name has appeared on dresses, sportswear, swimwear, loungewear, Vogue Patterns, and accessories.