The subject this paper focus on is how, in Italy, real estate investment and financial investment are, progressively, becoming interrelated sectors. The research carried out mainly involved examining how the risk factor can be reduced when variance in territory and category is used while investing to build-up a real estate portfolio. Research began with analysing the riskís sources (from economic trends to price ranges, reporting the circumstance variations and the allocation of frequency under a statistical approach) with the database of the Osservatorio sul Mercato Immobiliare di Nomisma ìObservatory of the Real Estate Market of Nomismaî that documented Italyís main 13 cities from 1988 to 2003. We also examined the risk involved when investment is done only in certain sectors of the market (residential, tertiary and commercial) through analysing trends in price and the respective correlations. More specifically this paper can be useful for the choice of real estate portfolio. Aiming at minimising the risk it first investigates the property rates of each real estate category in all 13 cities and then the relation these rates have with the main socio-economic features of the cities.