This research-related book gives geological history and the key exploration activities of oil and gas (petroleum) in the four major sedimentary rift basins in Kenya, where prospectivity is presently being carried out by international oil companies. The basins are Lamu, Anza, Mandera and the Tertiary Rift basins; and have undergone intermittent plate tectonic rifting processes during geologic period. The recent major oil discoveries in Lokichar basin, Tertiary Rift, by Tullow Oil Company in March 2012 has increased impetus for petroluem prospectivity in Kenya; although the sweet waxy crude oil is yet to be rendered commercially viable as further appraisal and development activities are being undertaken. Thus this work is aimed at providing an overview geologic history of the potential oil and gas basins which have so far been conducted by exploration companies. The source rocks, reservoir rocks, traps and caprocks (seals) have not been exhaustively studied, but the geology and structural framework reveal potential oil and gas lead structures for future exploration rationale. Given Kenya’s recent oil discoveries in Turkana County, there is need to intensify oil and gas search.