Theo Albrecht and his brother Karl revolutionized the German grocery market with a low-cost Business model. They had developed the supermarket as an outgrowth of their mother's small grocery store, which she had opened in 1913, in Essen, after Theo’s Father had developed emphysema as a miner. Theodor learned the grocery Business from his mother, in order to escape the fate of his Father in the mines. He and his brother Karl developed Albrecht Diskont, one of Europe’s largest chains of supermarkets, with the motto "The best quality at the lowest price," and now known by its acronym, Aldi. Forbes has estimated Theo's fortune from the supermarket chain as approximately £11 billion. Theodor and Karl Albrecht split the Aldi Company they founded in 1960 after a dispute about whether to sell cigarettes. The supermarket divided into two legally separate operating units with two geographical locations. Theodor's Aldi Nord set to operate in the north of Germany and Karl's Aldi Süd, set to operate in Germany's south. The progression of Aldi under Karl and Theodor Albrecht stands as one of Germany’s greatest success stories. Theodor retired from daily operations in 1993 and remained as chairman of the board.

Both Albrecht brothers have been reported by journalists to be highly reclusive; very little is known about their personal lives. The last published photo of Theo Albrecht dates to 1971, one day after his kidnapping. Another photo of the two Albrecht brothers together was taken in 1987 by Journalist Franz Ruch.

Theodor Albrecht died 24 July 2010, in his home town of Essen, Germany.

Theodor’s kidnapping in 1971 partially gives reason for his and the family’s hermit-like manner of existence. The kidnapping left an impact on Theodor’s private concerns, causing him to drive to work using a different route every day in an armored automobile. Little is known about Theodor Albrecht and the Albrecht family’s personal life. The Albrecht family are known to be very reclusive and described by Forbes as ‘more reclusive than the yeti’. Characterized by their privacy, Theodor has rarely been pictured by Photographers and he has never made a public statement. He was also claimed to be a devout Roman Catholic.