AbstractThis article is an account of primary levelling operations within the context of a national development plan. The scheme was originally conceived in 1960 by the then Commissioner for Surveys, Mr. C. W. Hindle, under whose direction a major part of the project has been undertaken. The author is in charge of the Computing and Survey Examination Section of the Tanganyika Survey Division and is responsible for the processing of observational data. Within the next two years, the primary levelling should reach Lake Victoria and interesting comparisons with Kenya and Uganda results will be available.