The present study was a randomized trial of the efficacy of psychosocial and injury prevention-based coach training programs for reducing fear of failure (FF) among youth swimmers aged 7 to 18 years. Results revealed that (a) psychosocial training increased coaches' use of reward/reinforcement, (b) the FF measure demonstrated strong factorial invariance over three measurement occasions in a 7-week period, (c) significant variability existed in intercepts, and (d) the type of training coaches received did not predict the slope of youth FF over the season after the variability in intercepts was modeled (i.e., the coach training program did not reduce youth FF significantly). This finding stands in contrast to previous research showing that a similar psychosocial coach training program reduced performance anxiety among 10- to 12 year-old boys. Despite the equivocal nature of the coach training literature, there is no evidence that these programs are harmful and psychosocial coach training may provide some benefits while the necessary conditions for consistent positive youth development effects are being determined.