"Jalan Sesama" was developed to address the developmental needs of Indonesian children ages 3 to 6 years. Using a randomized experimental research study design, this study examined the effect of a 14-week intervention on 160 children in the Pandeglang District in Indonesia's Banten Province. Results offer solid evidence that early cognitive skills, literacy, mathematics, health and safety knowledge, social development, environmental awareness, and cultural awareness significantly improved from baseline to post-intervention. Those with the greatest exposure to "Jalan Sesama" performed the best, even after controlling for baseline scores, gender, age, and parents' education. This paper describes how an educational media intervention can have great benefits, even in locales where the children face difficult hardships and lack basic resources. (Contains 1 figure and 8 tables.)