Pregnant adolescents have a higher risk of poor maternal and fetal outcomes, particularly in the setting of concomitant maternal alcohol and other drug (AOD) use. Despite numerous programmes aimed at reducing overall teen pregnancy rates and the recognition of AOD use as a risk factor for unintended pregnancy in adolescents, interventions targeting this specific group have been sparse. In adult drug-using women, financial incentives for contraception have been provided but are ethically controversial. This article explores whether a trial could ethically employ monetary incentives in adolescents with AOD use to promote the use of long-acting reversible contraception (LARC), with special attention to the relevant distinctions between adults and adolescents. We conclude that a trial of incentives to promote LARC in this patient population is ethically permissible if the incentives are small, are tied to completion of an educational activity to minimise the quick fix temptation and potential for non-attendance to the risks and benefits of LARC and are provided only to the adolescent after an assessment of her reasoning to rule out coercion (eg, by guardians) as motivation. Information about treatment for AOD use and follow-up care in case of problems with the contraceptive or desire for removal should also be provided. Before implementing such a trial, qualitative research with input from providers, potential patients and their parents should be conducted to inform the programme's specific structure.