Information about customers, products, and suppliers has become an essential resource for firms. Information and communication technologies (ICTs) contribute in different ways to the operation of firms, in terms of access to information, improvements to the business model, adequate knowledge management, and reduction of risks and costs, all of which can affect economic performance. The present study focuses on new technology-based firms (NTBFs), using a Mamdani fuzzy inference system with five inputs and five outputs, to assess the impact that ICTs have on economic performance, applying the reasoning of fuzzy logic. For the construction of the fuzzy inference system, a database of NTBFs founder-promoters was used. Information about ICTs (use of internet technologies, collaboration technologies, management technologies, support for decision-making and, search and data management) and measures of economic performance (sales, net profit, profitability, productivity and improvement of production costs) were extracted from the database for use in developing the model, which begins with definitions of the relationships between the input and output variables. The analyses performed indicated a slight change in economic performance through the interaction between ICTs measures. These findings will help firms make better decisions regarding the implementation of ICT infrastructure, allowing them to improve their economic performance.