A pilot project, implemented in 2 rural districts of Malawi between 2010 and 2011, introduced a mobile phone system to strengthen knowledge exchange within networks of CHWs and district staff. To evaluate the mobile phone intervention, a participatory evaluation method called Net-Map was used. At baseline, community health workers were not mentioned as actors in the information network, while at endline they were seen to have significant connections with colleagues, beneficiaries, supervisors, and district health facilities, as both recipients and providers of information. Focus groups with CHWs complemented the Net-Map findings with reports of increased self-confidence and greater trust by their communities. These qualitative results were bolstered by surveys that showed decreases in stock-outs of essential medicines, lower communication costs, wider service coverage, and more efficient referrals. As an innovative, participatory form of social network analysis, Net-Map yielded important visual, quantitative, and qualitative information at reasonable cost.