Centuries ago, the largely Muslim pastoral tribesmen to the east tended to migrate toward coastal regions, but this movement was inhibited to some degree by Portuguese colonization. In 1975, after the settlement of the guerrilla war against the Portuguese colonial administration, approximately 100,000 refugees returned from neighboring Senegal and Guinea.
In 1998, a civil war erupted in Guinea-Bissau, prompting tens of thousands to flee the capital for the surrounding countryside and several thousands to cross into neighboring countries. By June, some 300,000 people in the capital had been displaced. In July, several thousand local inhabitants and other nationalities left the country. Most refugees fled to Senegal and Guinea; others went as far as the Gambia and Cape Verde.
In 2000, the net migration rate was -2.9 per 1,000 population. In that year there were 19,000 migrants in the country, including 7,600 refugees. The government views the immigration level as satisfactory, but the emigration level as too high.