Organizations are turning toward behavioral interventions with the aim of improving employee well-being and job performance. Mindfulness training has been suggested as one type of intervention that can achieve these goals, but few active treatment randomized controlled trials have been conducted. We conducted a randomized controlled trial among employees of a midwestern marketing firm (n = 60) that compared the effects of 6-week mindfulness training program with that of a half-day mindfulness training seminar comparison program on employee well-being outcomes. Although both groups improved comparably on job productivity, the 6-week mindfulness training group had significantly greater improvement in attentional focus at work and decreases in work-life conflict, as well as a marginal improvement in job satisfaction compared with the half-day seminar comparison group. These findings suggest that although small doses of mindfulness training may be sufficient to foster increased perceptions of job productivity, longer term mindfulness training programs are needed to improve focus, job satisfaction, and a positive relationship to work. (PsycINFO Database Record (c) 2019 APA, all rights reserved).