The aim of the study was to evaluate differences in knee injuries and osteoarthritis between the dominant and non-dominant legs of former professional football players. The study cohort comprised 40 retired professional players with an average age of 49.2 years. Participants completed a questionnaire about their sports and personal history with special emphasis on knee injuries/operations of the dominant and non-dominant leg. Bilateral standing knee radiographs were taken. Overall, 29 footballers (73%) had experienced at least one moderate or severe knee injury and 18 (40%) had undergone at least one knee operation during their career. Among those injured, 14 (35%) players had suffered a dominant knee injury and 22 (55%) a non-dominant knee injury. Evidence of osteoarthritis (Kellgren-Lawrence scale > or = 2) was found in 17 (43%) dominant and 23 (58%) non-dominant knees. Professional football players have a significant risk of knee injuries and early osteoarthritis with preponderance in the non-dominant leg.