In Bangladesh, children under five are the most vulnerable to multimorbidity due to measles, diarrhea, colds, fevers, and allergic respiratory diseases. Bangladesh is mainly responsible for the 15 % of deaths in this age group that occur in low- and middle-income countries. Environmental causes include poor nutrition, limited access to healthcare, and indoor air pollution due to biomass burning. Prevalence rates are higher in the Rajshahi and Barisal divisions, which suggests that the regional disparities have continued. Other important determinants are maternal education, socio-economic level, and underweight status. Specific measures targeting these determinants-like improved healthcare facilities, nutrition, and sanitation-will be needed to decrease the burden of multimorbidity.