Distributive fluvial systems (DFS) have been recently recognised to form a significant proportion of the deposits of modern sedimentary basins. The deposits of ancient DFSs can be preserved in the stratigraphic record and form hydrocarbon reservoirs. Few detailed studies of this type of fluvial systems have been made and facies models for DFSs are incomplete; furthermore sandstone body architecture, crucial for reservoir characterisation, and its controls are poorly understood. This research provides detailed sedimentological and quantitative descriptions of the architecture of two outcrop examples of DFS successions: the Miocene Huesca DFS in Northern Spain and the Jurassic Salt Wash DFS in USA. A detailed fluvial architecture analysis has made it possible to develop unified facies and sandstone body classifications, and to quantify downstream trends in facies and sandstone body architecture. This quantitative outcrop data can potentially be used to characterise DFS deposits in the subsurface. Detailed sedimentological analysis of heterolithic overbank deposits of the Huesca DFS succession revealed that splay progradation was an important avulsion style, but statistical analysis showed no evidence of cyclicity in these deposits. Numerical object modelling was used to investigate controls on the sandstone body architecture. Implications of these studies to reservoir modelling are discussed.