OBJECTIVE:To investigate the past incidence of side strain injury and its associated factors in first-class cricket fast bowlers in Australia and England. DESIGN:Retrospective case series. SETTING:Professional cricket. PARTICIPANTS:Cricket fast bowlers who were professionally contracted full time at first-class level in Australia and England in 2011. All bowlers were male and aged 18 or older. A bowler was defined as a fast bowler if the wicketkeeper would take their stance back from the stumps. There were 207 participants. INTERVENTIONS:Not applicable. MAIN OUTCOME MEASURES:The association between bowling arm, player height, active trunk lateral flexion range of motion, side bridge endurance, volume of first-class cricket played, and the history of injury was determined. RESULTS:Over half of the bowlers had sustained at least 1 side strain in their career. Seventy-seven percent of primary injuries occurred in bowlers aged 24 or under. A higher proportion of injured bowlers had reached first-class volume in their career. Recurrence occurred in 30% of bowlers, with over 30% of these bowlers sustaining at least 1 further recurrence. Nearly half of all recurrences occurred within 2 years with a further quarter in the next year. The injury was not associated with any measured factors. CONCLUSIONS:Side strain is a common injury among first-class cricket fast bowlers, especially at younger ages. It was associated with the volume of first-class cricket played. Recurrence was common and occurred most frequently in the first 2 years after primary injury.