Piglets from group housing systems (GH) may be better prepared for weaning than those from individual housing of sows with litters (IH). It was rarely investigated on pig farms. We assessed how piglets play, fighting and biting behaviour before and after weaning were affected by the housing system and how the three behaviours are related to each other. We recorded behaviour in 5 GH and in 5 IH farms in Sweden. We observed 16 piglets from 4 litters in each farm on the day before weaning (W _ 1), the weaning day (W) and 5 days after weaning (W + 5). There was no difference between GH and IH farms in the frequency of playing, fighting or biting (p > 0.10). The frequency of playing and fighting differed significantly across the three observation days (p < 0.05). Play was higher on day W_ 1 and on day W than on W+ 5 (p < 0.05 and p = 0.01), fighting was lower on W_ 1 than on W or W+ 5 (p < 0.05 and p < 0.05). On W_ 1 and W+ 5, playing correlated with fighting (r = 0.785, p < 0.01 and r = 0.71, p < 0.05).