MultiREG is a multiregional input-output model that extends previous work on single-region models for Austria both in its geographic scope and its theoretical foundations. In a first version the model was completed in late 2004 and has already been used in long-term economic projections as well as in regional impact analysis. MultiREG is based on make and use tables for the nine Austrian regions (Bundesländer), distinguishing between 57 activities and commodities (2-digit NACE codes), which in the model itself are aggregated to 32 groups. These tables, as well as a matrix of interregional trade relations (for which a dedicated survey among Austrian firms was conducted), are derived for the year 2000. A block of econometric equations, which were estimated on regional time series of key variables (e.g., sectoral output, value added, investment, or employment), introduces strong dynamic elements into the static input-output framework. This block comprises private consumption and investment as well as cost functions which were derived in a General Leontief cost function framework. Additional dynamic adjustment is introduced by implementing time-varying input coefficients into the model. For the time being, foreign exports and imports are treated as exogenous (in the long-term projection exercise, exports were forecast in a panel regression framework, using assumptions about the economic development of Austria's 50 major trading partners).