An era of exceptionally fast population growth and migration in the Arab Gulf States may well be ending. For the last five decades or more, migration and demographic trends in the Arab Gulf States (Table 1) have been driven by oil and gas wealth. Between 1950 and 2015 these states have had the world’s highest rates of overall demographic growth: their total population multiplied by a factor ranging from 10 (Oman and Saudi Arabia) to 100 or more (Bahrain and UAE), compared with a less than threefold increase of the world’s population. Extremely fast population growth in the Gulf is generated by two factors. First, rapid natural increase of national populations, resulting from high (though declining) levels of fertility and low death rates. The above demographic transition has been enabled by states generously subsidizing their citizens’ families and health. The second factor consists of unmatched rates of net migration in response to tens of millions of job opportunities created by firms (e.g. construction) and households (domestic services). Specific patterns of migration characterized by the predominance of mostly unaccompanied men and specific legislations not granting migrants access to citizenship explain uniquely high sex ratios and proportions of foreign citizens. Such a pattern is not indefinitely reproducible, however.