OBJECTIVES: To explore knowledge of formal services and help-seeking behaviour for violence among Zimbabwean children aged 18 years and under. DESIGN: We use cross-sectional data from the 2017 Zimbabwe Violence Against Children Survey (VACS), which is nationally representative and had a 72% response rate for female participants and 66% for males; and anonymised routine data from one of the largest child protection service providers' (Childline Zimbabwe) call database. SETTING: Zimbabwe. PARTICIPANTS: We analysed data from 13 to 18 year old participants in the 2017 VACS and pertaining to respondents aged 18 years and under from Childline Zimbabwe's call database. MEASURES/ANALYSIS: We describe characteristics of children, and fit unadjusted and logistic regression models to estimate associations between selected characteristics and help-seeking knowledge and behaviours. RESULTS: 1339 of 4622 children aged 13-18 years surveyed for the 2017 VACS in Zimbabwe (29.8%) reported experience of lifetime physical and/or sexual violence. Of these, 829 (57.3%) children did not know where to seek formal help, 364 (33.1%) children knew where to seek help but did not, and 139 (9.6%) children knew where to seek help and did seek help. Boys were more likely to know where to seek help, but girls were more likely to actually seek help. During the 6-month period when VACS survey data were being collected, Childline received 2177 calls where the main reason for the call was recorded as violence against someone aged 18 years or under. These 2177 calls contained more reports from girls and children in school, versus the national profile of children who had experienced violence. Few children who did not seek help reported not wanting services. Most children who did not seek help reported that they felt at fault or that their safety would be put at risk by disclosure. CONCLUSION: Both awareness of services and help-seeking are gendered, suggesting that different strategies may be needed to support boys and girls to access the help they want. Childline in particular may be well placed to expand its outreach to boys and to receive more reports of school-related violence, and should consider efforts to reach out-of-school children.