Physical activity promotes children's awareness of the body. Children, to experience and to learn, need to be physically active and their innate physical activity is playing. Playing together means building relationships with peers, means learning how to use tools and space, means addressing egocentric behaviour toward rules' respect; in summary, it means learning "social conviviality and respect". The aim of the project "The moving body" was to favour children's physical and cognitive development and their social relationships. Gross motor physical abilities were assessed in 270 children attending the kindergarten. The children were grouped according their level of motor abilities to promote learning through older children's imitation. Structured games and playing were alternated to free time, and words such as physical activity, movement, and so on, were never used. Every month the children were asked to draw their own body to assess their body shape perception and their ability in representing it. All the children improved their physical abilities as compared to the beginning of the project; they strengthened their creativity and fantasy, inventing new and imaginative games, became more confident in their own capacities, and they learned how to deal and overcome, with a greater autonomy, difficult tasks. The body shape perception, and its representation as drawing, showed, especially among children 3 years old, remarkable progress. The importance of physical activity and play in kindergarten activities was evidenced through the significant improvement of children's several specific motor and psychosocial competences. (author abstract)