AbstractUnderstanding illness costs associated with diarrhea and acute respiratory infections (ARI) could guide prevention and treatment strategies. This study aimed to determine incidence of childhood diarrhea and ARI and costs of homecare, hospitalization, and outpatient treatment by practitioner type in rural Bangladesh. From each of 100 randomly selected population clusters we sampled 17 households with at least one child < 5 years of age. Childhood diarrhea incidence was 3,451 and ARI incidence was 5,849/1,000 child-years. For diarrhea and ARI outpatient care per 1,000 child-years, parents spent more on unqualified ($2,361 and $4,822) than qualified health-care practitioners ($113 and $947). For outpatient care, visits to unqualified health-care practitioners were at least five times more common than visits to qualified practitioners. Costs for outpatient care treatment by unqualified health-care practitioners per episode of illness were similar to those for qualified health-care practitioners. Homecare costs were similar for diarrhea and ARI ($0.16 and $0.24) as were similar hospitalization costs per episode of diarrhea and ARI ($35.40 and $37.76). On average, rural Bangladeshi households with children < 5 years of age spent 1.3% ($12 of $915) of their annual income managing diarrhea and ARI for those children. The majority of childhood illness management cost comprised visits to unqualified health-care practitioners. Policy makers should consider strategies to increase the skills of unqualified health-care practitioners, use community health workers to provide referral, and promote homecare for diarrhea and ARI. Incentives to motivate existing qualified physicians who are interested to work in rural Bangladesh could also be considered.