Over the past decade, the Kenyan Government has undertaken several water sector reforms in an attempt to increase water access. The most recent of these reforms (2002) was the privatization of water through the creation of autonomous Water Service Providers (WSPs). Among other things, that reform was sold as necessary to achieving the Millennium Development Goals (MDGs) with respect to water and sanitation. This paper uses Data Envelopment Analysis to evaluate the progress of the WSPs towards achieving the MDGs by 2015. Based on data availability and reliability, 44 WSP were selected and analysed on various efficiency measures, including technical efficiency and scale efficiency. The findings reveal that all WSPs are operating at significantly below capacity and unlikely to meet the MDGs. Over 50% of small WSPs have achieved less than 30% of targets considered necessary for achieving the MDGs. We propose the use of peer benchmarks as a way of mitigating poor performance.