High-technology industries make special contributions to a nation's long-term economic performance, and competition among the most advanced countries for high-technology production has increased strongly over the past two decades. The present paper, using an original data base and taxonomy for trade flows in high-technology products, demonstrates that in the period from 1970 to 1990 there were significant changes in the competitive positions of the United States, Japan and the former EC (now EU) countries. Japan undoubtedly achieved the highest gains, whereas US competitiveness has experienced a process of relative decline, and EU industry has suffered sharp losses in domestic and international markets, particularly in electronics. This general evolution, however, has been sharply differentiated with respect to the variuos product groups included in the high-technology category. The evidence of the paper seems to suggest that these changes constitute long-term competitive trends and may be attributed to structural factors as well as to macroeconomic and exchange rate fluctuations.