Objective: Community day-care centers (or crèches) are gaining popularity; access to these centers can reduce cognitive gaps. This paper describes the sustained impact of enrollment in day-cares on cognitive gains. Methods: As part of a larger study, a census of all children was conducted in 2012–2013 to identify children between 9 and 17 months of age in rural Bangladesh. A sub-sample of children (n = ~1000) were assigned to receive either a day-care or playpen. Children from two sub-districts were randomly selected and assessed at 9–17 months of age for cognitive and behavioral domains using the Ages and Stages Questionnaire-III. The same children were then followed-up with after one year to see if the scores obtained by the children in the day-care intervention were different from those enrolled in the playpen intervention using a difference-in-difference estimator. Results: Children enrolled in the day-care intervention performed better (in communication, gross-motor, personal-social, and problem-solving domains) than children enrolled in the playpens when followed up with after a one-year period. Total scores were 0.31 (95% CI 0.141–0.472) higher (p value < 0.001) among children in the day-cares. Family care indicators as well as the child’s and mother’s weight were significantly associated with sustained and increased cognitive gains. Conclusion and relevance: The cognitive and psychosocial improvements seen with short-term exposure to structured ECD programs (day-care) were observed to be sustained over time with continued exposure. Home stimulation and parental involvement add to the long-term benefits of ECD.