This paper describes the development of a rent index for Flanders, Belgium. This annual index, referred to as the huurprijsindex (rent index), is designed to detect changes in the rent of the overall stock of rental homes. We use the matched model methodology based upon repeat tenancy agreements, analogous to Case and Shillerís geometric repeat sales model, to estimate the rent index. We use recoded data on the tenancy agreements of nearly five hundred thousand rental homes; more than 30,000 representing repeat agreements between 1990 and 2010. The accuracy of the index is determined using the 95% confidence interval. Given our target (a geometric mean index value) and the characteristics of the dataset (large but without property characteristics) our repeat tenancy agreements method seems to be adequate for calculating a rent index for Flanders.