Background The huge proportion of child marriage contributes to high rates of pregnancies among adolescent girls in Bangladesh. Despite substantial progress in reducing maternal mortality in the last two decades, the rate of adolescent pregnancy remains high. The use of skilled maternal health services is still low in Bangladesh. Several quantitative studies described the use of skilled maternal health services among adolescent girls. So far, very little qualitative evidence exists about attitudes and practices related to maternal health. To fill this gap, we aimed at exploring maternal health care-seeking behavior of adolescent girls and their experiences related to pregnancy and delivery in Bangladesh. Methods and Findings A prospective qualitative study was conducted among thirty married adolescent girls from three Upazilas (sub-districts) of Rangpur district. They were interviewed in two subsequent phases (2014 and 2015). To triangulate and validate the data collected from these married adolescent girls, key informant interviews (KIIs) and focus group discussions (FGDs) were conducted with different stakeholders. Data analysis was guided by the Social-Ecological Model (SEM) including four levels of factors (individual, interpersonal and family, community and social, and organizational and health systems level) which influenced the maternal health care-seeking behavior of adolescent girls. While adolescent girls showed little decision making-autonomy, interpersonal and family level factors played an important role in their use of skilled maternal health services. In addition, community and social factors and as well as organizational and health systems factors shaped adolescent girls' maternal health care-seeking behavior. Conclusions In order to improve the maternal health of adolescent girls, all four levels of factors of SEM should be taken into account while developing health interventions targeting adolescent girls.