The province of Alajuela is located in the Northern Plains of Costa Rica. This province stretches from the Central Valley to Nicaragua. The capital city of the province is the city of Alajuela, which is located in the Central Valley of Costa Rica. This city is also home to Juan Santamaria International Airport (SJO). This is 1 of 2 Costa Rica International Airports.

Alajuela Province is bordered by the provinces Heredia, San Jose, Puntarenas and Guanacaste. The total land area of the Alajuela Province is 9,757 km². The population is 767,143 (May 2003). Alajuela Province is divided into 15 cantons as follows:

Cantons of Alajuela Province:

1. Alajuela
2. Alfaro Ruiz
3. Atenas
4. Grecia
5. Guatuso
6. Los Chiles
7. Naranjo
8. Orotina
9. Palmares
10. Poas
11. San Carlos
12. San Mateo
13. San Ramon
14. Upala
15. Valverde Vega