Background: Child marriage (<18 years) is prevalent in Pakistan which is associated with negative health outcomes including intimate partner violence (IPV). Our aim is to describe the types and circumstances of IPV against women who were married as children in urban slums of Lahore, Pakistan. Methods: Women of reproductive age (15-49 years) who were married prior to 18 years, for at least 5 years were recruited from most populous slum areas of Lahore, Pakistan. Themes for the interview guide were developed using published literature and everyday observations of the researchers. Interviews were conducted by trained interviewers in Urdu language and were translated into English. The interviews were tape-recorded, transcribed, analyzed and categorized into themes. Results: All 19 participants were married between 11 and 17 years. Most respondents were uneducated, poor and were working as housemaids. Majority of participants experienced verbal abuse, and threatened, attempted and completed physical violence by their husbands. A sizeable number of women reported unwanted sexual encounters by their husbands. Family affairs particularly issues with in-laws, poor house management, lack of proper care of children, bringing insufficient dowry, financial problems, an act against the will of husband, and inability to give birth to a male child were some of the reasons narrated by the participants which led to IPV against women. Conclusions: Women married as children are vulnerable to IPV. Concerted efforts are needed from all sectors of society including academia, public health experts, policy makers and civil society to end the child marriage practice in Pakistan.