The Government of Nepal aims to achieve full water and sanitation coverage by 2017. The bilateral Rural Water Supply and Sanitation Project in Western Nepal (RWSSP-WN) works with local governments in 14 districts, aiming to declare them open defecation free. This behaviour change communications evaluation explored how to improve RWSSP-WN’s present practices to reach the diverse target population in the Terai districts, where more than 1 million people still defecate in the open. The study reviewed RWSSP-WN’s present behaviour change triggering tools and related communications strategies. Our findings suggest that availability of subsidies seems to change how people think about sanitation and tends to eliminate willingness to pay for a latrine. We recommended strong advocacy for a no-subsidy policy, and more attention paid to alternative financing options with targeted support to the poorest of the poor. The present behaviour change triggering tools do work as intended, but there is a need to develop pre-triggering and post-triggering strategies to increase the overall impact. The pre-triggering strategy would ensure that potential barriers to change are identified and addressed before the actual triggering event, and that the key stakeholders are prepared for the actual triggering event. The post-triggering strategy is needed to continue motivating households to change via messages that tap into the drivers of change, addressing also the barriers which may keep each household from changing behaviour. This paper provides a number of recommendations applicable for those working with local governments and communities to increase the scope and scale of behaviour change triggering.