This paper presents a comparative analysis of the role played by migration in recent population growth trends in six regions of Spain. In recent years, total population has increased in Spain while there has been a strong arrival of immigrants except in the period after the Great Recession. This work contributes to a better understanding of how migration have influenced asymmetrically population growth in six regions of Spain. The databases used are the Residential Variation Statistics and the Natural Movement of the Population for the period 2008–2021. The compensating equation decomposition analysis shows different patterns of population growth across regions: while Spanish regions that show population growth are characterised by having a great positive migration balance of foreign-born individuals, and vice versa, the contribution of foreign-born individuals to births has stopped the fall in the population of those born in Spain. Consequently, all regions show a decline in the group of people born in Spain from native-born parents, except for the Community of Madrid due to the high number of entries of native-born individuals from other regions. Finally, we found differences in the immigrants’ contribution to total births according to country of birth.