A study was made of the relationship between weight, education, use of tobacco and alcohol, participation in athletics and family history of arthritis and severe osteoarthritis of the hip. Estimated relative risk of osteoarthritis was highest for those whose weight was at least 20% or more above ideal, having more than a high school education or with a familial history of arthritis. There was no association between severe osteoarthritis and participation in high school athletics or regular use of alcohol.