Due to a fall in the number of people moving in from abroad and a large number of people moving to Flanders and Wallonia, the population of the Brussels Region has not grown for the first time in 30 years. An analysis by the Brussels Institute for Statistics and Analysis (BISA) shows the population of the Belgian and Flemish capital is now stagnating. The stagnation is remarkable and, according to earlier forecasts, was not expected until a year later.
On 1 January 2026, the Brussels Region had a population of 1,255,834, according to data from Statbel and the National Register. That is just 39 more than a year earlier. 2025 marked the end of the uninterrupted population growth that Brussels has experienced since 1996. “We can even speak of a stagnation in Brussels’ population,” says the BISA in its latest demographic barometer.
Last year there were 5,103 more births than deaths in Brussels, in contrast to the other Belgian regions, where more people died than were born. Internal migration – that is, movements from Brussels to Flanders and Wallonia and vice versa – had a negative impact on Brussels’ population growth.
18,553 more people left heading for Flanders or Wallonia than there arrived in the opposite direction to Brussels. “However, this figure remains lower than in 2021, a record year for people leaving the Region,” according to BISA.
The fact that Brussels’ population has remained stable over the past year is mainly due to international migration: 48,179 people from abroad have settled in Brussels, whilst 34,191 Brussels residents have moved abroad.
“International migration remains the factor driving population growth in the Region the most. Nevertheless, this net international migration figure has fallen significantly compared with the past three years,” the BISA notes. Compared with 2024, the net international migration figure has fallen by 27.9 per cent.
Faster than expected
Whilst the number of international emigrants has remained more or less stable in recent years, the number of immigrants in particular fell sharply last year. In 2025, the inflow fell by over 6,000 people compared with 2024. Compared with 2022 – the year in which the war between Russia and Ukraine led to a large influx – there were in fact nearly 14,000 fewer international immigration movements. This is one of the lowest average figures of the past 20 years, the BISA says.
“This significant decline largely explains the stagnation of Brussels’ population in 2025,” the survey states. Demographers had not yet anticipated this stagnation during 2025. Forecasts in February of this year had still predicted slight growth in 2025 of 1,200 residents, but the actual figure was barely 39.
‘This difference can be explained by the fact that the number of births and international migration ultimately turned out to be lower than expected,’ the survey reads. According to earlier forecasts, Brussels’ population was not due to stabilise until 2026, followed by a slight annual decline until 2035.
Anderlecht overtakes Schaarbeek
At municipal level, the BISA notes that the population has increased in only 9 of the 19 Brussels municipalities, “which is far less than in recent decades”. Etterbeek saw the greatest relative growth, followed by Anderlecht, Ukkel and Vorst. In Evere, the City of Brussels, Ganshoren, Sint-Lambrechts-Woluwe and Sint-Pieters-Woluwe, the increase was very slight.
In the 10 other municipalities, there was a decline in population. This was most pronounced in Koekelberg, Elsene and Schaarbeek. Schaarbeek now ranks third in the list of Brussels’ most populous municipalities, after the City of Brussels and Anderlecht.
The BISA calculated that Ukkel was the only municipality where, in 2025, more residents arrived from Flanders and Wallonia than left for those two regions. “Everywhere else, there are more people leaving than arriving,” it states. This is particularly the case for the municipalities in the inner ring, such as Koekelberg, Sint-Gillis, Elsene and Sint-Joost.
International migration, on the other hand, had a positive impact on population trends in all municipalities, with the exception of Watermaal-Bosvoorde. This international immigration saw the sharpest increase in Sint-Gillis.
Fewer foreign nationals
In the 2026 demographic barometer, the BISA also paints a picture of Brussels’ population based on a number of indicators, such as the average age. This currently stands at 38.27 years, a slight increase of 0.20 years. The average age in Brussels has been rising for 10 years running. The population of Brussels is ageing, but remains young compared with Flanders and Wallonia, where the average age is 43.43 and 42.46 years respectively.
Finally, for the first time in 20 years, BISA has recorded a fall in the proportion of foreign nationals. On 1 January this year, 461,155 residents of Brussels did not hold Belgian nationality, nearly 6,000 fewer than the previous year.
According to the BISA, this is mainly due to the increase in the cost of acquiring Belgian nationality. This rose from 150 to 1,000 euros in the summer of 2025. 17,897 foreign residents of Brussels acquired Belgian nationality in 2025, compared with 14,508 in 2024. Last year, it was mainly Poles, French nationals and Syrians who were granted Belgian nationality.
At just under 37 per cent, the proportion of foreign nationals in Brussels remains very high compared with other cities such as Antwerp (23 per cent) and Liège (21 per cent). French nationals remain by far the largest group in Brussels, followed by Romanians, Italians, Spaniards and Moroccans. Ukrainians now rank sixth, having overtaken the Poles over the past year.