A vacuum pump 10 comprises a vacuum pumping mechanism 12 mounted for rotation by a shaft 14 and a brushless motor 16 for rotating the shaft. The vacuum pumping mechanism 12 comprises a turbo pumping mechanism 18 comprising a plurality of pumping stages, and a molecular drag pumping mechanism 20 comprising at least one pumping stage. Shaft 14 is supported for rotation by bearings 22. The motor 16 comprises a permanent magnet rotor 24 fixed relative to the shaft 14. The rotor 24 has four poles and a stator 26 has non-overlapping stator coils..