A selection experiment initiated in 1996 was designed to either select for (HP line) or against (LP line) feather pecking behaviour. The behaviour was recorded from White Leghorn hens at the age of 68 weeks (generation 0), 35 weeks (generation 1), 30 weeks (generation 2) and 27 weeks (generation 3). In adult hens, feather pecking was significantly higher among the HP line than the LP line. In generation two, there were 3.10 versus 1.37 bouts per bird per hour (HP vs. LP, respectively), 7.04 versus 3.58 pecks per bird per hour (HP vs. LP, respectively), and the proportion of hens observed feather pecking throughout the three hour observation period was 67 versus 56 % (HP vs. LP, respectively). In generation three, the statistics were: 4.56 versus 0.63 bouts per bird per hour (HP vs. LP, respectively), 13.9 versus 2.51 pecks per bird per hour (HP vs. LP, respectively), and the proportion of hens recorded feather pecking in the three hour observation period was 75 versus 49 % (HP vs. LP, respectively). The condition of plumage on the neck, breast, back, wings and tail, and overall plumage condition of LP hens in generation three was better than that of HP hens. Body weights did not differ between the lines in generation two, but HP hens were heavier than LP hens at 27 weeks of age in generation three.