Cost-effectiveness analyses (CEA), while present in the health and education sectors in international development research, remain rare among agricultural and rural development studies. This study conducts CEAs in a particular type of programmatic work in the sector namely, interventions that bring a gender lens to community-based advisory services in rural areas. Specifically, we consider two such programs one in Mozambique in which such advisory services aim to improve sustainable land management (SLM) practices in agricultural production, and the other in Tanzania to advise farmers on their land rights. We find that the gendered modality is consistently more cost-effective than the basic modality when considering varied outcomes and target groups. However, for any given modality, it is more cost-effective to improve outcomes for men than for women. A simulation of how cost-effectiveness would change if the program were scaled up geographically shows that expansion of the basic modality of the SLM program leads to improvements in cost-effectiveness, while the gendered modality displays nonlinear changes in cost-effectiveness along the expansion path, first worsening with initial scale-up and subsequently improving with further expansion. Acknowledgement : This work was undertaken as a part of, and funded by, the CGIAR Research Program on Policies, Institutions, and Markets, which is led by IFPRI. Amber Peterman and an anonymous reviewer provided helpful remarks during earlier-stage cost-effectiveness computations in the Tanzania case. We thank Ayala Wineman and Jessica Zhu for valuable research assistance with the data, and Lucy Billings for helping to coordinate with the Tanzanian implementing organisation. We are grateful for access to administrative cost data facilitated by Pedro Arlindo, Isabel Cossa, and Theresia Bujiku. Destino Abido Chiar conducted exploratory scoping fieldwork in Mozambique.