Research has supported mindfulness as a predictor of athletic success. This study used a parallel trial design to examine the benefit of a brief one-session mindfulness training for performance on an individual, nonpacing, closed skill athletic task (i.e., golf putting). All participants (N = 65) answered questionnaires and engaged in two trials of the putting task. Participants were randomly assigned to an intervention or control group using a simple randomization strategy. Between trials, the intervention group received a mindfulness intervention. Mindfulness intervention included psychoeducation, reflection upon previous sport experiences, an experiential exercise, and putting applications. Repeated-measures ANOVAs demonstrated that the intervention group exhibited more successful outcomes on objective putting performance, flow state experience, and state anxiety (p < .05). Results suggest mindfulness may prevent performance deterioration and could produce psychological benefits after a brief training session.