Outcrops in the central and southern Mandawa Basin have been examined and studied in detail, with the emphasis on describing facies and facies associations. This has been done to provide information about the depositional environment for the Upper Jurassic Mitole Formation. The sedimentary field data, together with petrographical (thin section analysis, SEM) and mineralogical studies (XRD) have further been combined to outline the diagenetic history of the formation. The study area is located in the central and southern parts of the Mandawa Basin, which is located in the southern coastal part of the United Republic of Tanzania. The evolution and stratigraphy of the Mandawa Basin is closely linked to the opening of the Indian Ocean and the break-up of the Gondwana continent. The Mitole Formation was deposited from the Kimmeridgian (Upper Jurassic) to the Berriasian (Lower Cretaceous). During this time, the study area was subsiding at an increased rate, following the successful break-up of the Gondwana continent, but it was also a time when the coastline regressed as large amounts of clastics was introduced to the basin from paleohighs. The Mitole Formation comprises two members, the Lower Mitole Member and the Upper Mitole Member. In the central and southern Mandawa Basin the studied profiles which represent the Mitole formation display depositional environments within different shallow marine settings. The study reveals that variations in the sequence of diagenetic alterations for the different profiles are closely linked to the depositional facies and the porosity and permeability of the rock at deposition and during burial. The Lower Mitole consists of sandy siltstone, interbedded with oolitic limestone and was deposited close to or below the fairweather wave base in the lower shoreface to the offshore transition. The profile is highly calcite cemented by sparry calcite cement. The calcite cement was precipitated early during burial, which have occluded most of the porosity. The Upper Mitole Member consists of sandstones deposited in several shallow marine facies. Early calcite cementation is common in the shoreface sandstone, while sandstones deposited in a foreshore environment experienced mechanical infiltration of clay minerals in an early stage, which later transformed and degenerated into authigenic clay coatings consisting of smectite and interstratified illite/smectite.