For improvements to the safety and welfare of racehorses to be possible, it is essential to have access to basic descriptive information about the veterinary incidents encountered during horseracing. A 3 year surveillance study (1996-1998) was conducted by The Jockey Club into racing injuries, other postrace clinical problems and fatalities from all 59 British racecourses (mainland Britain only) to identify risk factors. During the survey there were 222,993 racing starts: 106,897 starts in flat races on turf (47.9%), 26,519 starts in flat races on all-weather surfaces (11.9%), 30,932 starts in chases on turf (13.9%), 51,786 starts in hurdle races on turf (23.2%) and 6,859 starts in National Hunt flat races (3.1%). Information was recorded about age of horses, racing surfaces and clinical events observed or attended by a veterinary team of 2 clinicians and one veterinary surgeon employed by the racing authority. Of the 2358 clinical events reported (1.05% of all starts), 1937 involved the musculoskeletal system and 421 involved other body systems. Six hundred and fifty-seven incidents (0.29% of starts) resulted in death or euthanasia. Eighty-one percent of limb injury reports involved forelimbs and 46% involved flexor tendons/suspensory ligaments. Nonlimb problems included epistaxis (0.83/1000 starts), 'exhausted horse syndrome' (0.47/1000 starts) and paroxysmal atrial fibrillation (0.20/1000 starts). Incidents including fatalities per 1000 starts were 24.7 from chases, 19.45 from hurdle races, 8.46 from National Hunt flat races and 3.97 from flat races. The overall tendon injury was higher in chases than in hurdle races, even though age-specific rates of tendon injury were higher in hurdle races than in chases. The risk of injuries per start increased significantly with age, while softer racing surfaces were associated with fewer fatalities and injuries than firmer surfaces. The survey described in this paper has provided an up-to-date description of the fatal and non-fatal horseracing incidents under conditions on mainland Britain, enabling progress to be made towards improving the safety and welfare of racehorses.