Portuguese is a very rich language in terms of dialects, each with its particularity. Most of the differentiation between them is the pronunciation of certain vowels. Between Brazilian Portuguese and European Portuguese, there are differences in vocabulary, pronunciation and syntax, especially in popular varieties, while between educated Brazilians and Portuguese these differences are reduced. There are several similarities in pronunciation, syntax and simplification in grammar use between vernacular Brazilian Portuguese and vernacular Angolan Portuguese. But there are no differences between cultivated European and Angolan Portuguese.

Some apparent differences between the two varieties in lexicon are not really differences. In Brazil, the common term for carpet is tapete. And, in Portugal, it is alcatifa. However, many dialectal zones in Portugal use tapete and other areas in Brazil use alcatifa. This applies in several such apparent differences, except in the new terms, such as ônibus in Brazil, which is autocarro in Portugal. A conversation between an Angolan, a Brazilian and a Portuguese from very rural areas flows very easily. The most exotic Portuguese dialect is vernacular São Tomean Portuguese, because of the interaction with local Portuguese Creoles, but even with this one there are no difficulties when talking to another person from another country.

A dialect can also be selected to be a variety of the language, due to prestige, culture or socio-economical factors. There are two officially used dialects in the Portuguese language. The one of Rio de Janeiro (and, in some manner, São Paulo) for Brazil and of Lisbon and Coimbra for Portugal, Portuguese speaking African countries and East Timor, due to politics the two varieties are somewhat written differently. These differences are to be eliminated because Brazil and Portugal have made an orthographic agreement. Because the African countries are involved and did not yet approved, it is not yet in force, thought Brazil has made some pressure, with the support of Portugal, in the African countries to approve the agreement.

Spoken varieties of Portuguese are: European and African Portuguese, Brazilian Portuguese, São Tomean Portuguese, Galician Portuguese (considered by philologists).

In fact, Galician is a co-dialect of Portuguese. It has many differences not observed in other varieties due to Spanish influence.

Portugal presents the wider variety of dialects in the Portuguese language. Although the country is very small, a city or village can have its own particular dialect. The Nortenho dialect in Portugal presents many regional words only used by them and the dialect has (possibly) unique features not found in other Portuguese dialects. But because they are intelligible, even when using local words, Portuguese speakers do not understand what they speak as dialects.

Brazilian Portuguese pronunciation is more consistent throughout Brazil than the Portuguese spoken in Portugal. Even then, almost all the regional traits and characteristics of European Portuguese are present either in standard Brazilian Portuguese or in one or more of the regional Brazilian dialects.