A condition increasingly present in the labor markets in Brazil is called into question: contractual flexibility. A historical condition in which workers are subjected to precarious forms of work relations. Taking as a reference data from the formal labor market in three medium-sized cities in Rio Grande do Sul (Caxias do Sul, Passo Fundo and Santa Cruz do Sul), it is indicated that the dynamics of the labor markets in these cities affect ways of inserting workers. from the assumption of «social disengagement»; a phenomenon that, in the medium-sized cities investigated, is an expression of the predominance of jobs with low wages and low qualification requirements, of occupational experiences marked by discontinuity, of the constant experience of unemployment.