Relations between children's (n = 213) mother-reported effortful control components (attention focusing, attention shifting, inhibitory control at 42 months; activational control at 72 months) and mother-reported shyness trajectories across 42, 54, 72, and 84 months of age were examined. In growth models, shyness decreased. Inhibitory control and attention shifting predicted higher levels and lower levels of shyness at 42 months (the intercept), respectively. Inhibitory control negatively, and attention shifting positively, predicted the shyness slope. Children with higher inhibitory control had relatively more rapid decreases in shyness. Children with higher attention shifting had relatively slower decreases in shyness. Activational control was negatively correlated with the shyness intercept. Effortful control components should be examined separately, rather than in combination, in relation to shyness in the future. If results are replicated, it may suggest that fostering attention shifting and activational control development helps prevent, or maintain low levels of, shyness during childhood.