This paper explores the perceived causes of infertility, treatment-seeking for infertility and the consequences of childlessness, particularly for women, among a predominantly Muslim population in urban slums of Dhaka in Bangladesh. In-depth interviews were conducted with 60 women and 60 men randomly selected from Urban Surveillance System clusters of the International Centre for Diarrhoeal Disease Research, Bangladesh. Case studies of 20 self-perceived infertile women who had previously participated in a study on the prevalence of sexually transmitted diseases and other reproductive tract infections were taken, and three traditional healers were interviewed as key informants. In both groups of respondents, the leading causes of infertility were perceived to be evil spirits and physiological defects in women and psychosexual problems and physiological defects in men. Herbalists and traditional healers were considered the leading treatment option for women, while for men it was remarriage, followed by herbalists and traditional healers. Childlessness was found to result in perceived role failure, with social and emotional consequences for both men and women, and often resulted in social stigmatisation of the couple, particularly of the woman. Infertility places women at risk of social and familial displacement, and women clearly bear the greatest burden of infertility. Successful programmes for dealing with infertility in Bangladesh need to include both appropriate and effective sources of treatment at community level and community-based interventions to demystify the causes of infertility, so that people know why infertility occurs in both men and women and and where best to seek care.