This paper reports the full results of a baseline survey on access to water for domestic use and social accountability in four districts of Dar es Salaam, Tanzania’s largest city, and Morogoro, a provincial town around 200 kilometres west of Dar. From 7th to 29th March 2018, the survey team interviewed 2,154 adults about their access to water, perceptions of water quality, sanitation and hygiene facilities, readiness to pay for water services, social accountability for water provision, civic engagement and social demographics.Scottish Funding Council Grant Number SFC/AN/12/2017