Lei Clijsters was born on 6 November 1956 in Opitter, started his football career with local Opitter FC. Later, he played for Club Brugge KV, but left the club after a disappointing two-year stint; he started his career as a midfielder.
In 1988, Clijsters also won the Golden Shoe award as league's MVP, and eventually retired with Liège at almost 37. Immediately, he starting working as a manager with former club Patro Eisden, then moving to K.A.A. Gent,K.F.C. Lommel S.K. (July–December 1998), K. Tesamen Hogerop Diest (two spells, in 1999–2000 and November 2000 – June 2001) and Mechelen (July–November 2000).
Afterwards, Clijsters managed the professional tennis career of his daughter Kim. After her retirement, "Lei" became coach of third division club Tongeren, with which he had also played, in October 2007. He resigned in January 2008, after his family announced that he was suffering from a serious illness. Details were kept secret, but in February the Belgian press reported it to be metastaticmelanoma and that treatment was not working.
On 4 January 2009, Leo Clijsters succumbed to the illness at age 52. Upon his death, Belgian newspapers like Het Laatste Nieuws revealed that he suffered from a recurrence of a melanoma which had spread to the lungs and other organs, having already experienced a bout of this condition twenty five years earlier.