In this paper, we propose a methodology to compute series for the tangible capital stock of Portuguese firms along with consistent flows in the period 2006-2020. We benefit from the richness of the accounting data at the micro level, which encompass detailed information about flows and stocks by asset category, making use of a modified version of the Perpetual Inventory Method to take into account the specificities of the data. In particular, given the change in the accounting standards in 2010 with the switchover from POC to SNC, we develop a strategy to overcome this break in the balance sheet data. We conclude with a comparison of our derived measure with the accounting series, and provide a brief overview of the evolution of capital stocks and flows of Portuguese firms over the period covered.