<p>This paper observes the changes of the influence of intellectual capital elements together with some financial elements on the financial performance of Portuguese firms before and during the COVID-19 crisis in high and medium–high technology manufacturing sectors with using the ordinary least squares regression method and the value added intellectual coefficient (VAIC) model. The results show the consistency of the positive effect of human capital efficiency in both the pre-crisis and crisis periods as well as the positive effect of structural capital efficiency and the strengthened positive effect of capital employed efficiency together with the strengthened negative effects of leverage and firm age when coming into the COVID-19 crisis. Therefore, the findings confirm the significant roles of the talented and well-educated employees as a typical feature of the human capital and the development of digital and information techniques in production and management processes for high and medium–high technology firms; increasing the efficiency of physical capital and decreasing the burden of finance as efficient cost reduction strategies can benefit these manufacturing firms during the crisis. Suggestions for these firms include investing more in specific types of structural capital, keeping the efficiency of physical capital and cutting down the costs of financial capital, and especially avoiding over-investment in human capital during the crisis. The most important contribution is that the findings can help managers realize the importance of intellectual capital during the COVID-19 crisis and then allocate limited resources to keep comparative advantage.</p>