Latent growth curve modeling was used to investigate the longitudinal link between attachment, effortful control (EC), and maladaptive development during middle childhood. In a community sample, children (Time 1: n = 157; M[subscript age] = 10.91) and their mothers were examined three times over a two-year period. Attachment was operationalized at a more strategic (self-reported trust in maternal support) and more automatic level (secure base script knowledge). Mothers reported about children's EC and maladjustment. Secure attachment was associated with higher EC, but EC development was only linked with baseline self-reported trust. Also, EC indirectly linked baseline self-reported trust with change in externalizing and internalizing problems over time. In addition, self-reported trust was indirectly linked with change in externalizing problems over time through EC development. EC, and, less robustly, EC development were linked with attachment and change in emotional and behavioral problems.