In order to study the preferred combination of the illuminance level and correlated colour temperature (CCT) and the preferred CCT of different ethnic groups in office lighting, a full-scale experiment was conducted in an office room with a light-emitting diode (LED) luminaires. Fifty-three observers from three different ethnic groups (Asian, European and African) rated nine different preset lighting situations after performing different office activities. The combination of 750 lx with 4000 K was statistically significantly preferred for office lighting. It was also found that the impression of brightness increases with a higher CCT and that people feel more stimulated under a higher CCT compared to a lower CCT. The European group preferred a lit environment under CCT 4000 K for office lighting and with the Asian and African groups the preference between 4000 and 5000 K depends upon illuminance levels.