The aim of this study was to determine the cortisol levels in Schutzhund dogs during training, in order to highlight a relationship between different work programmes and adrenocortical activity. Fifteen Schutzhund dogs (12 males and 3 females) were used: six dogs with the highest level of training (title IPO-3, group IPO-3), and nine animals without title IPO (group IPO-0). Animals of the two groups followed two different training programmes. The programme followed by IPO-3 dogs consisted of a period of intense work for each section (section A - tracking phase, section B - obedience phase and section C - protection phase; period 1) and a period of reduction in the intensity of the training (period 2). On the other hand, IPO-0 dogs underwent a constant work intensity throughout the experiment. The faeces and hair cortisol content was measured by RIA. In all dogs the exercise induced a significant increase of faecal cortisol concentrations as compared with the levels at rest; the faecal levels of this hormone were higher in IPO-3 than in IPO-0 dogs both on days when animals were not doing physical activity and on days of work, indicating a greater exercise-related adrenocortical stimulation. Training intensity induced a modification in faecal cortisol concentrations while these were not affected by the type of work (Sections A, B and C). Correlation between hair and faecal cortisol levels was also checked; hair cortisol levels correlated positively with those observed in faeces.