Capital gains tax is charged on the sale of all property in Portugal. Whilst this is less of a problem if you have found your dream home and want to spend many years living there, it is a more significant consideration if your intention is to buy a property for the short term or for investment purposes.
If you purchased the property prior to January 1989 there is no tax on the gain realised on sale. In all other instances, 50% of the gain is taxable and inflation relief can also be applied if the property was held for more than 2 years. The gain is then added to your other income for the year and taxed at the scale rates of income tax.
Despite the potential for high rates of tax on sale, there is main residence relief available if you reinvest the proceeds into another main home in Portugal (or the EU/EEA). Certain other conditions apply but in general, the gain will be exempt from taxation if all the proceeds are reinvested. Any portion not used to purchase another main home (or reinvested in a savings plan/ pension) will be taxed.