The present study, factors affecting accessibility of water supply options was conducted in Kisauni, Mombasa County with a main objective of finding the most accessible water supply in terms of quality, quantity and cost among the existing water supply options and also to access the role of solar powered desalination in improving accessibility of water supply in Kisauni. With water scarcity problem growing worse as the world population grows, water supplies need to be increased at household levels. Lack of clean drinking water to households has already had a significant effect on international development. In Mombasa 50% of the diseases reported are attributed to lack of access to clean water. Solving water crisis in its many aspects is one of the greatest challenges facing mankind, it is no wonder many are encouraged to look at the sea where the majority of world’s water belong. Seawater desalination has been seen as a long-term freshwater source.The study used questionnaires to get information on cost and quantity of water supply available to the residents. The questionnaires were randomly distributed to residents depending on their willingness to participate in the study. Water samples were collected from the various water sources using sterilized plastic water samplers to determine its quality through chemical and biological analysis. The study established that the available water supply options in Kisauni are not accessible in terms of quality, quantity and cost with tap water meeting WHO drinking water threshold but being highly costly and unavailable while Groundwater is readily available at a very affordable cost, but the quality is unfit for human consumption unless used with further treatment. Groundwater quality is both chemically and biologically way above the WHO specified threshold, with salinity and conductivity measuring up to 478.5 mg/l and 2180 µs/cm against the specified 250mg/l and 2000 µs/cm respectively. General Coliform counts and E.coli were 2100MPN/100ml and 1200MPN/100ml respectively against the specified nil. The study finds the use of small scale solar still to desalinate brackish groundwater as the most accessible. With a base area of 0.72m2 producing an average of 1.97litres of desalinated water and 150m2 expected to produce 410 litres per day other factors like weather conditions being held constant. The study recommends that more research and awareness should be conducted on solar desalination to help improve water supplies in the area.