Alive & Thrive integrated a nutrition intervention into an existing maternal, neonatal, and child health programme in Bangladesh, documenting improvements in women's micronutrient supplement intake and dietary diversity. In this paper, we examined how well the nutrition intervention was implemented and which elements of implementation explained intervention impact. Using survey data collected from frontline health workers and households in areas randomized to receive the nutrition‐focused programme or standard program, seven intervention elements were measured: time commitment, training quality, knowledge, coverage, counselling quality, supervision, and incentives.