Recent studies suggest attention may be trained as a skill. While a large body of literature suggests that expertise in domains like chess or music requires 5,000 to 10,000 hours of practice, most previous studies examined changes in attention following far less training. We report performance on different attention tasks by 32 Buddhist meditators, who engage in attentional training for up to 10 hours per day. Participants completed computerized tests of reaction time and accuracy measuring vigilant, alerting, orienting, and conflict attention. Fourteen meditators with over 5,000 hours of training showed improved alerting, vigilance, and conflict resolution compared to age- and gender-matched controls, while 18 meditators with less training showed only improved conflict resolution. These studies indicate that attention can be modulated by meditation training; while some attentional components require the 5,000 hours of training typical for expertise across domains, others may require less. Alternatively, the enhanced conflict resolution seen in meditators may reflect a quickly achieved but transient effect of meditation, such as increased relaxation.