The article analyses data obtained from anonymous excerpts of records from the parish registers for the historical centre of Prague. It was found that the city's growth was fed primarily by immigration, as the high mortality rates hindered growth by natural increase. The level of infant and child mortality observed was on the whole higher than what was found in other locations in the Czech lands. Even in Prague in the 17th and 18th centuries features of the 'urban' reproductive regime were discovered: low nuptiality, a low fertility rate, and conversely a high mortality rate. A specific feature was the structural changes in fertility toward the end of the 18th century, with an unprecedented increase in the number of children born to unmarried mothers (mostly of whom were originally from outside Prague). The stagnation of population growth in Prague at the end of the Thirty Years War continued into the 1660-70s and the population only began growing again in the 1680s. This positive development was interrupted in the 1730s and then especially during the wars in the middle of the 18th century, but toward the end of the 18th century the pace of population growth began to accelerate.