During the 1990's, Brazil experienced a remarkable increase in its unemployment rate, The intensity of this process was higher for unskilled and semiskilled workers than for skilled. The objective of this paper is to evaluate the role of skill-biased shifts in the structure of labor demand for the patterns of unemployment rate by skill. In order to do so, a model with two kinds of shocks, aggregate and relative, was used. The aggregate shocks are those that are equal to all skill groups, and the relative ones are related to labor demand structural changes. The parameters of the model were estimated using PNADs (Pesquisa Nacional por Amostra de Domicílio) data from 1990 to 1999. Then, the impact of each shock on unemployment rate by skill was evaluated. According to the evidence found in this paper, the demand for skilled workers increased compared to semi-skilled and unskilled, leading to a reduction on skilled workers relative unemployment rate.