This article focuses on four different criminal markets: counterfeiting, illegal firearms trafficking, gambling and waste management. Despite recurrent allegations that these markets have a high mafia presence, there is a lack of reliable estimates of their sizes and the revenues that they generate. Figures in reports and media vary significantly, and the methods used to obtain them are often obscure. This study develops four different estimation methodologies with which to estimate the four criminal markets in Italy at the national and regional levels. Considering that these are the first attempts to estimate these markets, the aim of the article is to stimulate debate on how to improve measurement of the crime proceeds from these criminal markets.