The real (meaning "royal", plural: réis or [archaic] reais) was the unit of currency of Portugal from around 1430 until 1911. It replaced the dinheiro at the rate of 1 real = 840 dinheiros and was itself replaced by the escudo (as a result of the Republican revolution of 1910) at a rate of 1 escudo = 1000 réis. The escudo was further replaced by the euro at a rate of 1 euro = 200.482 escudos in 2002.

Before the middle of the 19th century, many different denominations were minted, often with values in terms of the real which increased over time. For example, the cruzado was introduced at a value of 324 real branco in the reign of João II. It was fixed at a value of 400 réis during João III's reign and this remained the value of the silver cruzado until the reign of Pedro II, when it was revalued to 480 réis. Meanwhile, the gold cruzado rose in value to 750 réis in the reign of João IV, then to 875 réis in the reign of Afonso VI before its demise. Two denominations which did not change their values were the vintém of 20 réis and the tostão of 100 réis.

The last 1 real coins (excluding colonial issues) were minted in the 1580s. After this time, the smallest coins were worth 1½ réis. These were minted until around 1750, after which the three réis coin became the smallest circulating denomination. From the early 18th century, the standard gold coin was the peça, valued at 6400 réis (7500 réis after 1826).

In the late 18th century and early 19th century, copper coins were issued in denominations of 3, 5, 10, 20 and 40 réis, with silver 50, 60, 100, 120, 240 and 480 réis and gold 480, 800, 1200, 1600, 3200 and 6400 réis. Some of these coins showed denominations which were no longer accurate due to earlier revaluations. These included the 240 and 480 réis which were inscribed 200 and 400.

In 1837, a decimal system was adopted, with copper coins (bronze from 1882) of 3, 5, 10 and 20 réis, silver coins for 50, 100, 200, 500 and 1000 réis and gold 1000, 2000, 2500, 5000 and 10,000 réis. In 1875, the last 3 réis coins were issued, with cupro-nickel 50 and 100 réis issued in 1900.