In equine long-distance endurance competitions, nearly 40% of the starters are eliminated at a veterinary control. Excessive racing speed, the nature of the race venue and the distance covered have been identified as risk factors for elimination. The objective of the present study was to assess whether speed, venue country and the horse's age are risk factors for elimination, on the basis of individual electronic timing datasets collected during long-distance endurance competitions. Data were obtained for 7,032 horses entered in 80 to 160 km endurance rides in four countries. For each horse and each competition, the datasets included the distance covered, age, average speed, cardiac recovery time and heart rate measured at Vet gate for each phase of the race, and the outcome of the race (i.e. qualification or elimination). For eliminated horses, the reason and phase of elimination were also recorded. An analysis of variance was used to identify and compare variability factors and differences in recorded variables in qualified vs eliminated horses. In the study population, 39% of the starters were eliminated - mostly due to lameness (64%) or metabolic reasons (15%). The eliminated horses displayed a higher speed and worse recovery during the first phases of the race (P<0.05). The mean speed was higher in events organised in the United Arab Emirates, in 2-star rides and in intermediate/mature horses; these factors were associated with slower cardiac recovery and a greater risk of elimination. Our results confirm that excessive speed is a major risk factor for elimination in endurance rides and further indicate that factors such as the venue country, the event distance and the horse's age are also involved. With a view to increasing completion rates and reducing fatal injuries in endurance races, preventive measures should take these factors into account.