Even after graduating from school Dieter Schwarz was a partner in that of his father, Joseph Black in 1930, originally as a fruit wholesaler Lidl & Co was founded and under the name of Foodstuff Lidl & Schwarz KG entered advanced companies. 1968, then age 29, he opened in Backnang its first supermarket called Handelshof.As in 1970 following the death of his father inherited the fruit wholesale to Metro, belonged to him already 30 sold Lidlstores. The design of the first after discount concept in working Lidl-market (1973 Mundheim opened), he continued up to market. 1977 saw Dieter Schwarz took over the company entirely discounted. The Lidl Stiftung & Co. KG, finally it has developed into one of Europe's largest retail chains.

The assets of Dieter Schwarz is estimated at 11 billion euros.Nevertheless, he is considered to be thrifty and cautious.

On 1 February 2007 Dieter Schwarz was a "generous benefactor and well-esteemed fellow-citizens", patron of art, culture, education and universities, and founder of the honorary citizenship awarded of the city of Heilbronn.He is also the carrier of the merit ofBaden-Wuerttemberg.

Founded in November 1999 Dieter Schwarz Foundation to promote education and science and is named after him.

Dieter Schwarz is married since 1963 with Franziska, born Weipert. The black couple has two adult daughters. He was heavily influenced by the membership in the Evangelical Free Church congregation.

He is considered to be reclusive, concealed his identity, refuses interviews from a strict and Lidl also lets the company headquarters in Baden-Württemberg, Neckarsulm guard heavy.There is little existing photos of him