Weaning sheep under farming conditions combines two factors that can be potentially stressful agents: (1) physical separation of mother and young and (2) modification of lambs' feeding habits. The purpose of this study is to measure the consequences on animal welfare of two weaning procedures currently used in France: (1) progressive weaning (PROG) with daily separation starting when lambs are 3.5 weeks of age increasing in duration until definitive weaning at 3 months and (2) sudden weaning (SUDD) at 3 months. Forty Ile de France ewes and their 60 lambs were used in the study. In the PROG group, a sharp increase in the vocal activity of ewes and lambs was recorded during periods of temporary separation. However, animals became accustomed to the procedure with repeated separations and very few behavioural reactions were recorded when lambs were definitively weaned at 3 months of age. In the SUDD group, ewes and lambs were very vocal at weaning but signs of disturbance were no longer noticeable after two days. In ewes, the cortisol levels were not affected by separation from their young whatever weaning method was used, but an increase in leucocyte levels was recorded in SUDD ewes on the day of weaning. In lambs the number of coccidial oocysts excreted at 9.5 and 16.5 weeks of age was higher in PROG than in SUDD lambs. Their growth rate was not affected by the daily separation. In conclusion, neither method seems highly stressful in sheep. However, lambs are more sensitive to parasite infestation when separation from the mother is repeated until weaning. Finally, sudden weaning, which involves less work for the breeder, can be used without heavy disadvantages on welfare.