Thirty six sows and litters were used to study how suckling behaviour was influenced by grouping of piglets and changing sow location under controlled conditions. Control sows (C) remained in farrowing pens with crates until weaning at 28 days. In treatment 1 (T1), piglets from three litters were grouped in the farrowing pens while the sows were still confined in the crates. This was done by removing the solid wooden partitions between pens from Day 11 after farrowing until weaning. Treatment 2 (T2) was as T1, but on Day 21 each of the three sows was moved to a different crate within the group of three adjacent pens and left in that crate until weaning. After weaning, the piglets were monitored in flat decks for 3 weeks. On Day 21, piglet weight was not significantly different (C 6.25, T1 6.17, T2 6.19 kg, s.e.d. 0.24). Daily live weight gain of T2 was significantly reduced after the sows changed location (C 286, T1 281, T2 229 g/d, s.e.d. 18.3, P < 0.05, Day 21–28). Therefore, weaning weight in T2 was slightly lower than C and T1 (C 8.28, T1 8.04, T2 7.80 kg, s.e.d. 0.26). The percentage of suckling attempts which were successful was reduced on the day of grouping (C 87.3%, T1 63.1, T2 74.3, s.e.d. 6.2, P < 0.05) and on Day 21 in T2 (C 90.7%, T1 91.6, T2 60.5, s.e.d. 4.9, P < 0.01). Cross-suckling increased ( P < 0.05) to 61% and 51% of piglets on Day 21 and 27, respectively, in T2, while T1 remained at less than 10%. After weaning, C piglets spent more time fighting (C 8.8, T1 3.4, T2 0.8% of time, s.e.d. 1.1, P < 0.05) with the result of higher damage scores (C 0.72, T1 0.20, T2 0.29 bleeding scratches/piglet, s.e.d. 0.14, P < 0.01 on Day 35). However, the performance of the piglets was not significantly different. Grouping piglets disturbed suckling patterns only on the day of grouping but reduced fighting after weaning. Changing the sows' location disrupted the suckling patterns and increased cross-suckling but did not affect long term performance.