Currently, the greatest population density is recorded in the Community of Madrid (605 inhabitants per square km.), followed by the Basque provinces (295), the Canary Islands, Catalunya, Balearic Islands and Valencian Community (all with between 200 and 100 inhabitants per sq. km.).

The lowest density is found in Castilla-La Mancha, Aragon, Extremadura and Castilla-Leon, with less than 30 inhabitants per sq. km.

It is evident that these demographic imbalances are due to socioeconomic inequalities, since the internal migration corresponds to an exodus from areas with little opportunity to those experiencing a more dynamic economic development. However, the diversity of the urban industrial zones which receive the influx has prevented a more marked territorial difference in population distributions, as has happened in other countries including some European nations.

As the population is distributed over a territory of just over five hundred thousand square kilometres, its density stands at 76.8 inhabitants per sq. km., slightly higher than that of Greece, for example, and considerably lower than the rest of Europe.

     Cities with 200,000 inhabitants or more
     in 1991: 
     ---------------------------------------
     City         Inhabitants (in thousands)
     ---------------------------------------

      1 Madrid                 2,910
      2 Barcelona              1,624  
      3 Valencia                 753
      4 Seville                  659
      5 Zaragoza                 586
      6 Malaga                   512
      7 Bilbao                   369
      8 Las Palmas               342
      9 Valladolid               328
     10 Murcia                   319
     11 Cordoba                  300
     12 Palma de Mallorca        297
     13 Vigo                     275
     14 Hospitalet               269
     15 Alicante                 261
     16 Gijon                    259
     17 Granada                  254
     18 La Coruna                245
     19 Badalona                 207
     20 Vitoria (Gasteiz)        205
     -------------------------------------

Source: National Statistics Institute