ObjectivesWe evaluated a military resilience intervention which aimed to help UK military recruits to manage their personal health and well-being more effectively.MethodsTrainers within six pre-existing training teams were randomly allocated by team to deliver a resilience-based intervention (SPEAR) or usual training (control) during recruit training. 23 trainers delivered SPEAR; 18 delivered the control training. 707 recruits participated (n=358 SPEAR and n=349 controls). Outcome measures were obtained before and after recruit training and 3 months later. Measures of post-traumatic stress disorder (PTSD), common mental disorder (CMD) symptoms, alcohol use, homesickness and mental health stigmatisation were obtained at baseline. Repeat baseline scales plus measures of help-seeking, cohesion, leadership and training impact were obtained at the two follow-up points.ResultsResponse rates were 91.7% (baseline), 98.1% (post) and 73.6% (follow-up). Following adjustment for potential confounders, levels of PTSD, CMD symptoms, alcohol misuse, help-seeking and homesickness were not significantly different between groups at any measurement point. Stigmatisation was significantly lower among SPEAR recipients at baseline but was not significantly different at the two follow-up points. Following adjustment for mental health confounders, there were no significant between-group differences in perceptions of leadership and cohesion and in ratings of six training outcomes at the two follow-up points.ConclusionsWe found no evidence that resilience-based training had any specific benefit to the health and well-being of UK military recruits.