This longitudinal study examined developmental changes in conflict inhibition and error correction in three cohorts of children (5, 7, and 9 years of age). At each point of assessment, children completed three levels of Luria’s tapping task (1980), which requires the inhibition of a dominant response and maintenance of task rules in working memory. Findings suggest that both conflict inhibition and error detection and correction improve significantly during middle childhood. When cognitive demands were high, conflict inhibition, as shown by initial response accuracy, improved steadily across middle childhood. In contrast, the ability to detect and correct for errors improved between 5 and 6 years of age. Further, variability in conflict inhibition decreased with age and individual differences in conflict inhibition were stable across the 1-year period in the 7- and 9-year-old cohorts, but not 5-year-old cohort. These findings are discussed in relation to previous research on the development of inhibition.