Its gothic church, inaugurated in 1543, in the centre of town, has a conspicuous tiered spire.
A portion of Brussels Airport is located in Diegem. Diegem's situation just outside the Brussels-Capital Region and close to the R0 (the Brussels orbital motorway) mean it has a large number of business premises.
Its postal code is 1831.
Brussels Airlines has its corporate head office in the b.house on the grounds of Brussels Airport and in Diegem. Brussels Airlines formed in 2006 as a result of a merger between SN Brussels and Virgin Express.
Primary schools in Diegem include Gemeentelijke Basisschool De Fonkel and Parochiale Basisschool. GISO Machelen provides secondary education to Diegem residents. Bibliotheek Machelen-Diegem is the public library of the town.
- Sainte Catherine's and Saint Cornelius' church (in Diegem)
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- "Village History".