The present dissertation deals with Participatory Design carried out by the Investigation Laboratory in Living Design - LILD/ PUC-Rio under the Design and Emotion view-point, in which the focus is the feelings people have about the objects that surround them and the built environment. The author contrasts Participatory Design - characterized by the user´s active involvement in almost all stages of the planning process - against the idea that the design should be a result of the work of a solitary genius, who does not need to know the user´s reality and desires. The dissertation presents some researchers´ thoughts that assert that the user has to be the designers´s partner throughout the entire product design process and that the design has to play a social and ethical role. The dissertation promotes the theoretical meeting between the authors and Professor José Luiz Mendes Ripper, LILD coordinator, to whom the designer has to prepare the world to all. This meeting occurs around aspects of Participatory Design practice observed throughout the LILD work field, under the author participant observation. After presenting examples of objects developed by LILD in partnership with users, the author brings out some reflections and identifies the important feeling of coauthorship present in the practice of Participatory Design.