This paper describes the matrimonial and reproductive behaviour of Italians who migrated to Belgium after the Second World War. Migrants were either already married, or later became married, to other Italians. Among the children of migrants, men equally chose Italian or Belgian wives but women tended to prefer Italian partners. Italian-Belgian marriages were more frequent among the better educated groups. Family size is smaller among migrants marrying after migration and in heterogamous marriages. Significant differences in birth intervals are found when marriage occurred before or after migration, between generations, and between homogamous and heterogamous marriages.