Background: Most research on migrant fertility focuses on immigrants from high-fertility countries who have moved to countries with lower fertility. Little is known about the fertility of immigrant women from countries where fertility is lower than in the destination country.

Objective: This study investigates fertility rates among women from low-fertility countries who have moved to a country where fertility is comparatively higher (Norway).

Methods: Register data on immigrant women from Poland, Lithuania, and Germany are used to calculate total fertility rates by duration of stay and to explore differences between family migrants and women who migrate for other reasons, between women of different ages at arrival, and between those who emigrated again and those who remained in Norway.

Results: Among immigrants from low-fertility countries, total fertility rates are elevated in the first years after migration. This is particularly true for women from Poland and Lithuania, who often arrive as family migrants and at peak fertility age (25 to 34 years).

Contribution: The fertility among migrants from low-fertility settings is often highest right after migration, particularly if they arrive as family migrants. Women with nonfamily reasons for migration have a time lag between immigration and peak fertility. The results underscore the usefulness of taking reason for and age at migration into account when studying immigrant fertility.