Farmed fallow deer (Dama dama) fawns need to receive care and help from their mothers and be stimulated by other individuals, including their peers. This helps them to learn to live in a group, establish their place in the herd, acquire food, perceive dangers, survive, and initiate reproductive behavior. Adequate analysis of changes in behaviour conducted by deer breeders can be helpful in management of the animals. Furthermore, the knowledge of the time when any disturbance in the natural behaviour of animals should be avoided may contribute to improvement of their welfare. The aim of the research was to analyse the behaviour of fawns in the early rearing period and the influence of weather conditions. The observations were conducted in July 2017 and 2018. The fawns most frequently performed the observed activities in the morning and evening. The ritual playing and suckling bouts were most often noted in the evening. With an increase in air temperature and a decrease in humidity, the young fallow deer followed the doe and vocalized to call the mother, probably to persuade her to hide in a shaded place. A higher frequency of suckling was noted at an increased air temperature and humidity, but the suckling time was reduced with the increasing air temperature. A greater wind speed was associated with a higher frequency of allosuckling. The study showed that the natural behaviour of fawns, which has an impact on their functioning in the herd, should not be disturbed in the morning and evening.