The use of co-investment activities to motivate farmers to carry out sustainable land management is increasingly recognized. Several co-investment efforts have been implemented to combat land degradation and increase agricultural production in the Ethiopian highlands. Nevertheless, these co-investment activities have not been documented. Moreover, the impacts of these activities have not been evaluated. This study presents a co-investment initiative for sustainable land management in the Galessa watershed in Ethiopia. It documents successful co-investment activities that trigger farmers to carry out land management practices, and assesses the impact of these activities on farmers’ land management investments. The most important co-investment activities that trigger farmers to invest in land management are co-investments in awareness creation, water provision, technology, and governance. Of these activities, co-investing in water provision is most successful, because it directly solves one of the basic needs of farmers in the watershed. Results reveal that the experimental group of farmers (participants in the co-investment initiative) – compared to the control group (nonparticipants) – invested significantly more in land management practices such as soil bunds, composting, and tree planting. This article concludes that use of multiple co-investment activities are crucial to trigger farmers to invest in land management in Ethiopia.