Diarrhea remains one of the major causes of death in Bangladesh. We studied diarrheal disease risk and healthcare seeking behavior among populations at high risk for diarrhea in Dhaka, Bangladesh. Data were obtained from a cross-sectional survey conducted during April and September 2010. The prevalence of diarrhea was calculated by age-group and sex. A generalized estimating equation with logit link function was used to predict diarrheal disease risk and seeking care from a professional healthcare provider. Of 316,766 individuals, 10% were young children (<5 years). The prevalence of diarrhea was 16 per 1000 persons among all ages; young children accounted for 44 per 1000 persons. Prevalence of diarrhea was significantly higher (p=.003) among younger males (<15 years) compared to that among younger females. In contrast, prevalence of diarrhea was significantly higher (p<.0001) among older females (≥15 years) compared to that among older males. An increased risk for diarrhea was observed in young children, males, and those staying in rented houses, lower family members in the house, using non-sanitary toilets, living in the area for short times, living in a community with less educated persons, living in a community with less use of safe water source for drinking, or living close to the hospital. About 80% of those with diarrhea sought care initially from a non-professional healthcare provider. Choice of the professional healthcare provider was driven by age of the patient, educational status of the household head, and hygienic practices by the household. The study reaffirms that young children are at greater risk for diarrhea. Like other developing countries most people in this impoverished setting of Dhaka are less likely to seek care from a professional healthcare provider than from a non-professional healthcare provider, which could be attributed to a higher number of diarrheal deaths among young children in Bangladesh. Dissemination of information on health education, increasing the supply of skilled healthcare providers, and low-cost and quality healthcare services may encourage more people to seek care from professional healthcare providers, thus may help reduce child mortality in the country. Further studies are warranted to validate the results.