This study was aimed at the design of a Soil Geographic Database (SGDB) as part of a Soil Information System (SIS), for the improved management of soil and land resource data relevant to an area around Lake Naivasha in Kenya. Emphasis has been given to the rescue of existing data available in different formats from a variety of sources and to the improvement of user access to adequate soil information for multiple purposes. The methods adopted for SGDB data modelling and for SIS development are the relational data model and the iterative structured information system development method, respectively. Two components of the SIS were designed: a relational database structure having twelve relations, and a prototype information system architecture consisting of four subsystems. The study proposes a working approach for multi-source data integration and standardisation in a common database structure. Correlation tables have been developed to handle the multi-category issues when dealing with different soil survey approaches and soil classification systems. A nested database design approach is applied to integrate data resulting from surveys at different levels of detail and map scale.