Front-line workers (FLWs) are necessary to deliver large-scale interventions to improve maternal and child nutrition. However, low and middle-income countries (LMICs) face issues of FLW performance in service delivery, knowledge, and motivation. This study investigates how interventions like training, supervision, and mass media improved FLW delivery of nutrition services by comparing the performance of FLWs in Bangladesh and Vietnam in areas with and without intensive support from Alive & Thrive (A&T). In the A&T-intensive areas (A&T-I), FLWs received specialized training, job aids, and regular supportive supervision, whereas in non-intensive areas FLWs received only standard government supervision. In assessing data collected in 2010 and 2014, research shows that FLWs in A&T-I areas had higher scores in training, supportive supervision, and mass media exposure. These higher scores were correlated with improved knowledge and motivation, which, in turn, improved service delivery and knowledge for end-user mothers and children. This study highlighted the possibilities for training, supervision, and mass media to improve FLW knowledge and motivation, which directly impacts maternal and child nutrition intervention delivery at scale.