<p>This multi-method investigation examined attentional focusing, effortful control, and coparenting interactions as correlates of toddlers’ emerging behavioral regulation to combine two unique lines of research – one that has linked attention regulation strategies to behavioral regulation within delay of gratification tasks and one that has linked temperamental effortful control to behavioral regulation. Seventy-five children, ranging in age from 28 to 38 months (<i>M</i> = 32.0, <i>SD</i> = 2.2), and both of their parents participated in a 2-hour laboratory visit on a university campus. Toddlers were observed in a variety of paradigms, including two prohibition (i.e., “don’t touch”) tasks that were coded for toddlers’ attention deployment and latency to touch as well as a family freeplay which was coded for coparenting behavior. Parents completed questionnaires about their toddlers’ temperamental effortful control and internalized conduct. Neither effortful control nor coparenting behavior contributed uniquely or interactively above and beyond attention deployment to toddlers’ behavioral regulation in the gift delay task; however, effortful control and coparenting behavior interacted to predict toddlers’ behavioral regulation in the toy prohibition task and parents’ reports of toddlers’ internalized conduct. Specifically, these findings suggest that children, based on their temperamental characteristics, are differentially susceptible to the environment such that toddlers low in effortful control exhibited less behavioral regulation when parents engaged in high levels of undermining coparenting. These findings could inform the development and test of interventions targeted at children who may be at risk because of their temperament.</p>