Our epidemiological study investigated lateral epicondylitis (tennis elbow) among 150 nonprofessional male tennis players (75% of the players approached consecutively) interviewed and examined physically at four local tennis clubs. The interview and examination covered over sixty possible risk factors, including demographic data, playing habits, anatomical measurements and racket characteristics. The "average" painfree player is 38 years old, has played tennis 11 years, and plays 5.5 hours a week, usually with a racket whose head area is 570 cm2. The "average" tennis elbow sufferer is a 45-year-old player who has been playing 16 years and has played 8 hours weekly before onset of pain with a racket whose head area is 613 cm2. Multivariate analysis indicated that number of playing years has no independent effect beyond its association with age. Playing hours per week, current age and age at pain onset have independent significant effects on number of pain episodes (0-7). Weekly number of playing hours is the best predictor of pain category (none, one or more currently or in the past).