To determine whether laying hens find the flicker of fluorescent light aversive, their preferences were tested individually in a two-room testing chamber in which each room could be illuminated by either incandescent or fluorescent lights. The rooms were joined by a central compartment which acted as a light baffle and through which the birds could easily pass. The level of illumination in the two rooms was carefully matched and other resources such as food, water and nest-boxes were available in both rooms. The preferences of 16 mature light hybrid hens which had experience of both fluorescent and incandescent lighting were recorded during a 6-h test period on each of 2 d with the light sources in the rooms being switched on the second day. Overhead video cameras recorded the position and the behaviour of the birds throughout testing. On each of the test days, the hens spent significantly more time in fluorescent light than they did in incandescent light (each day: P < 0.01). When data from both test days were combined, the birds spent on average 73.2% of their time under fluorescent light and only 26.8% under incandescent (P < 0.001). Frequency distributions of ingestive behaviour, nesting, preening, resting and walking indicated that the birds performed all activities in both rooms and in both types of light. These results indicate that the birds either did not perceive the flicker of the fluorescent lights or perceived the flicker and did not find it aversive, and that they found some aspect of the fluorescent light more attractive than incandescent. Key words: Lighting, fluorescent, incandescent, behaviour, poultry