The article traces the efforts made in constructing Input €“output Tables for Tanzania Mainland and in particular looks at the key sectors that have been identified in the various Input-Output Tables. From the five Input-Output Tables considered in this study, 13 sectors have been identified as key sectors that have influenced the economy of Tanzania Mainland for the period from 1969 to 1992. A closer look at the recent 1992 Input-Output Table seems to indicate that 4 sectors of Grain Milling, Hotels and Restaurants, Spinning and finishing textiles, and financial intermediation are the current most influential sectors in the system of the economy of Tanzania Mainland. Accordingly these key sectors may be used in the projection and simulation exercises in order to assess the viability of plan targets and to explore the implications of alternative development strategies in the planning process.
