For seven years I have been developing an extension project and several research projects in the field of children's playfulness, and specifically about the Toy Room with the undergraduate students of the Licenciatura em Pedagogia course of the Universidade do Estado de Minas Gerais - Ituiutaba Unit. We consider that playing... is a serious thing! Therefore, the initial formation in Pedagogy must form qualified professionals, with the necessary knowledge to act in the scope of the several types of Brinquedoteca, because the children who frequent this space must be stimulated the ludicity, the creativity, the imagination. There are several research and extension projects approved in funding agencies (FAPEMIG, PAPqe PAEx) that we discuss the importance of playing for the holistic development of the child. In the last two years, we received awards due to the classification score in competitive calls. Thus, we gathered in this book, articles results of some researches in the field of Hospital Playroom, School Playroom and University Playroom.