There were 46.4 million residents in the country as of the first of January, a drop of 72,335, or 0.16 percent, from the same time last year, according to figures from the National Statistics Institute released on Thursay.
The number of births edged up by 0.1 percent last year to 426,303, ending a five-year decline which coincided with the nation's economic downturn.
Spain's migratory balance meanwhile was negative last year once again, with 102,000 more people leaving the country than arriving.
While 307,000 people moved to Spain last year, 409,000 left the country, mainly foreign residents. Spain's two largest groups of immigrants, Romanians and Moroccans, both shrank.
The British community remained Spain's third-largest foreign group even though the number of British nationals living there fell by 2.02 percent to 303,776.
Not only are foreigners returning home — many Spaniards are also leaving to look for work abroad.
Nearly 79,000 Spanish nationals left Spain last year while just over 41,000 returned to the country.
The Spanish economy, the eurozone's fourth largest, returned to growth last year with an expansion of 1.4 percent although the unemployment rate remains high at 24.8 percent, the highest in the European Union after Greece's.
Associations representing people who have left Spain questioned the figures for the number of people who have left the country, accusing the conservative government of downplaying the figures.
One group, Marea Granate, said it estimates that the number of Spaniards who left Spain was actually ten times higher than the figure provided by the statistics office.
It said it had compiled figures for the number of Spaniards who registered with the social security system of just ten nations last year and the figure came to 89,209 — higher than the statistics office's figure for the total number of Spaniards who left last year.
Marea Granate gave Uruguay as an example. While the statistics office said 668 Spaniards moved to the Latin American country last year, it said officials in Uruguay tallied the arrival of 6,462 Spaniards.
“The Popular Party government constantly minimises the real emigration figures,” it said in a statement.