The aim of this study was to assess salivary cortisol level in dogs during admission and a three-day stay in a pet hotel. The study involved 20 dogs admitted to a pet hotel for a stay lasting for at least three consecutive days. The study group consisted of 10 small dogs and 10 medium-sized dogs, eight females and 12 males. Saliva was collected each day to assess cortisol levels. A stay in a hotel is a stressful situation for dogs, as evidenced by the increase in the salivary cortisol level. The highest salivary cortisol level was observed on the day of admission to the hotel. The median salivary cortisol level in the dogs on the consecutive days was 2.7 ng/ml on admission, 2.1 ng/ml after 24 hours, and 1.9 ng/ml after 48 hours. Depending on the size of the dog, the median salivary cortisol level was 2.8 ng/ml, 2.9 ng/ml and 2.4 ng/ml in the small dogs and and 2.2 ng/ml, 1.7 ng/ml and 1.2 ng/ml in the medium sized dogs on the consecutive days.