Diffusion of innovations theory provides a useful framework for exploring how attributes of the individual, intervention, and social system, converge to allow the spread of new ideas/behaviours from a source (e.g. implementing organisation) to an individual (e.g. community members) via different communication channels (e.g. mass media, interpersonal communication) and influence . In this paper we use data from a multidisciplinary evaluation of SASA! to gain understanding of the communication channels and intervention attributes through which IPV interventions can stimulate behaviour changes in intimate relationships. The SASA! Study was conducted in Kampala, Uganda between 2008 and 2012 and comprised a cross-sectional cluster randomised control trial (RCT) , qualitative studies , a process evaluation and a costing study . The RCT showed the intervention to be associated with lower acceptability of IPV, as well as reductions in women’s experiences of IPV—past year experience of all types of IPV was lower in intervention compared to control communities, with statistically significant effects observed for past year experience of high intensity emotional aggression and controlling behaviours, and cessation of physical, sexual and emotional IPV where it was previously occurring . The aim of this paper is to examine through which communication channels SASA! diffused and the intervention attributes that contributed to its effect. Specifically, we analyse the associations between different communication channel exposures and reported positive change in relationship quality (as it is on the pathway to IPV cessation) from our larger quantitative survey sample. Qualitative data is examined to elucidate the intervention attributes that facilitated engagement with the intervention and uptake of new ideas and behaviours in intimate relationships.