This analysis examines structural change in the State of Washington economy through an input-output analysis. The results indicate that significant changes in interindustry demand occurred between 1963 and 1972. For the Agricultural sector, the interindustry demand in 1972 was more than in 1963. In contrast, the Energy sector used more interindustry demand in 1963 than in 1972. For the Trade and Finance, Insurance, and real estate sector, there was also more interindustry demand in 1963 than in 1972. The empirical analysis leads to similar conclusions when interindustry demand is calculated using alternative methods.