He was at least 6'10" tall, and was usually billed at over 7' tall. His great size was a result of excessive growth hormone, a condition known as pituitary gigantism, and led to him being dubbed "The Eighth Wonder of the World".
He was the third of five children. Roussimoff was a good student but left school after 8th grade because he did not feel having a high school education was necessary to live and work on a farm that was not his own. As an adolescent, he worked on the farm, completed an apprenticeship in woodworking, then worked in a factory that manufactured engines for hay balers, but none of these jobs brought him any satisfaction.
Roussimoff trained at night and worked as a mover during the day in order to pay living expenses. Montreal-native promoter and wrestler, Frank Valois, met Roussimoff in and became his business manager and close adviser. For the next few years, Roussimoff began making a name for himself wrestling in England, Germany, New Zealand and Africa. Roussimoff made his Japan debut in , billed as "Monster Roussimoff", wrestling for International Wrestling Enterprise.
Wrestling there as both a singles and tag team competitor, he quickly won the company's tag team championship alongside Michael Nador.
It was during Roussimoff's time in Japan when doctors first informed him that he suffered from acromegaly, a hormonal disorder, which can lead to gigantism. After his stint in Japan, Roussimoff moved to Montreal, Canada.
