This study investigated the effect of additional roughage in the outdoor area on activity and aggressive behaviour among organic growing/finishing pigs. The study included two experiments and behaviour was studied on four occasions per experiment. In experiment 1, 377 pigs were allocated randomly to either a control treatment (C) or treatments with access to additional roughages; hay (H), grass silage (GS) or whole crop barley silage (BS). Each treatment consisted of three groups. In experiment 2, 138 pigs were randomly allocated to the C or the GS treatment with two groups per treatment. Pigs were housed indoors with straw in the lying area and with a concrete outdoor run, where H, GS and BS pigs were given roughages ad libitum in hedges. Statistical analysis was performed with group as the statistical unit in SAS Proc. Mixed. Pigs given roughage stayed outdoors more often and were more active than control pigs (p<0.05, for both). C pigs were rooting in straw in the lying area more often than GS and BS pigs, which suggests that additional roughage motivated the pigs to explore and forage although straw was provided. However, we did not find any difference in time spent on eating the different roughages (H, GS and BS). The frequency of aggressive behaviour in the indoor lying area was lower among roughage pigs than C pigs in experiment 1 (p=0.009) and was lower, though not significantly, in experiment 2 (p=0.121). In experiment 1, pigs stayed outdoors more often with a tendency of eating roughage more frequently later in the rearing period, which resulted in a lower aggression level with increasing age of the pigs. Our results indicate that access to additional roughage is an important resource that might influence pigs to be more active, and which can reduce aggressive behaviour among the pigs.