The aim of this paper is to present an analysis of the socioeconomic factors which may affect the terrestrial Digital TV diffusion in Brazil. Such an ex ante analysis is supported by system dynamics models that represent non-linear relations influencing users' interest for this new media. The model inputs are derived from market surveys which reflect users' demand and expectations for Digital TV services. The basic model evaluates penetration of  terrestrial digital TV according to the number of households with Digital TV receiver. Although the proposed simulation model is based on Bass diffusion model, other factors influencing diffusion of digital TV were implemented, due to deployment alternatives and Brazilian socioeconomic conditions, specifically the disposable income per socioeconomic class. Furthermore, it is shown how this and other conditional variables, such as attractiveness of new services, might affect digital receiver adoption in the Brazilian society.