Real estate appraisal is a very important activity in the modern economies. As such, the main objective of this paper is to analyse the relationship between yields and income rents in assessing the Portuguese real estate appraisal on the main Portuguese municipalities. Real estate market data series were analised during a four-year period (2006-2009) using income rents in ?/m2 . With the data it was possible to determine the average income rents and the capitalization rates, and carry out a comparison through a clusters analysis. The results show that the income approach can be used to explain the supply market value of the dwellings at municipal level.