Percentage of population in the ages between 18-74 with immigrant background by Region.

[Cernunnos]

How well would you say immigrants are integrated in Portugal?

Depends on what and how you define integrated.

Many blacks only speak Portuguese because that is their native tongue but they like in other countries never fully integrate and are notorious criminals. Some are mid class and a few intelectuals.

Brazilians are too diverse to say, can be anything, from a upper class Brazilian with European background who lives in Cascais to the average pardo favelado who plays funk at Public Transports. Only pardos here who are very rich are the football players or an ocasional very famous Funk performer who randomly can have a residence here.

South Asians or Eastern Asians are 0 integrated except for Catholic Goans who are very integrated perhaps those are the most integrated ethnic minority. I've seen some Chinese kids speaking Portuguese and having non-chinese (white) friends but it is rare.

Eastern Europeans assimilate quickly unless they come in droves and form a ghetoo. If they come as individuals or single families they integrate quite quickly, they learn the language with ease. Brazilians rarely leave their accent unless they migrate early, marry a Portuguese and live many years somewhere else without much Brazilians.

To sum it up: Most aren't and won't assimilate, some are assimilating and a minority is fully integrated.

[Valenman]

Less than Spain
But in the case of Portugal, immigration is not so dangerous, since most of the immigrants are Portuguese speakers and in many cases have recent Portugal/European ancestry.