The Research & Development & technological innovation (RD&I) are among the main sources for the development and growth of developed and developing countries. To stimulate investment in RD&I by private companies, the government resorts to several mechanisms, such as financial and non-financial incentives, such as tax incentives. Thus, this work is aimed at analyzing, through an exploratory research with private companies from various sectors of the Brazilian economy, the use of tax incentives for RD&I in the private sector, set forth in  the main public incentive mechanism for RD&I enforced by the Federal Government of Brazil - Lei do Bem. The findings show the importance of public policies to promote investment in RD&I in Brazilian private firms, but also highlight difficulties and improvement suggestions for the use of tax incentives provided for by the Good Law - Lei do Bem, which results in a number far below the expectations of the Federal Government of Brazil.