Biotechnologies consist in the use of living organisms, or parts of organisms, to make or modify products. These techniques have broad application in agriculture, biomedicine and food industry. Recent progresses in cell and molecular biology originated a biotechmological revolution, here exemplified by genetic engineering. This paper discusses the economic impact of modern biotechnologies, stressing the bioindustry strategies, the problems of biosafety (mainly the release of genetically modified organisms into the environment) and the problems of patents originated by genetic engineering. The role of biotechnologies in developing countries is discussed. In these countries the biotechnologies represent new opportunities for economic and social development but, also, bring the risk of loosing comparative advantages.