Under-representation of female adolescents in HIV clinical trials may inhibit their access to future prevention technologies. Domestic violence, broadly defined as violence perpetrated by intimate partners and/or family members, may affect trial participation. This study describes violence in the lives of adolescents and young women in Tanzania, explores use of the Women's Experience with Battering (WEB) Scale to measure battering, and examines the associations between battering and socio-demographic and HIV risk factors. Community formative research (CFR) and a mock clinical trial (MCT) were conducted to examine the challenges of recruiting younger (15-17) versus older (18-21) participants into HIV prevention trials. The CFR included qualitative interviews with 23 participants and there were 135 MCT participants. The WEB was administered in both the CFR and MCT. Nineteen CFR participants experienced physical and/or sexual violence and 17 % scored positive for battering. All married participants reported partner-related domestic violence, and half scored positive for battering. Many believed beatings were normal. None of the single participants scored positive on battering, but one-third reported abuse by relatives. Among MCT participants, 15 % scored positive for battering; most perpetrators were relatives. Younger participants were more likely to report battering. Adolescents experienced high rates of domestic violence and the WEB captured battering from both partners and relatives. The level of familial violence was unexpected and has implications for parental roles in study recruitment. Addressing adolescent abuse in HIV prevention trials and in the general population should be a public health priority.