The aim of this paper is to assess the effect of different types of corporate tax reforms, recently implemented in Italy, on the debt choices of companies. To do so, we merge the information of a micro-simulation corporate tax-model (MATIS), with an empirical representation of the modified pecking order model, and we apply this analytical framework to a panel of Italian manufacturing companies. Main results suggest that: (a) the Italian fiscal code of the period 1982-1999 is well implemented by MATIS model, which delivers reliable predictions of fiscal account data for a sample of about 20,000 companies; (b) the reforms analyzed are able to induce similar reductions in firms' leverage, when compared with the situation prevailing before tax reforms. However, the routes through which the two reforms operate are different (mainly relative cost of capital in the first case, cash flow in the second), tracing some important differences in the overall evaluation of the two normative changes.