The ecological ICMS was first used to distribute a share of the ICMS revenue in the state of Parana in 1991. In the Minas Gerais State, the Ecological ICMS was implemented in 1995 with the “Robin Hood Law”. The objective of this study was to evaluate the change in the ICMS distribution in Minas Gerais caused by the introduction of the ecological criterion. Results showed that the distributional effects were small mainly due to the small percentage allocated to counties, benefiting mainly poor and small counties and harming most counties. A logit model was estimated to check the determinants of counties on receiving the Ecological ICMS. Results showed that counties area and the ICMS amount received by the value-added criterion had positive effect on the receiving probability. Regional variables were also important.