Wheat is a major winter crop in southern Brazil. To maximize its productivity, there should be no biotic or abiotic restrictions that can affect the yield components. Thus, the objective was to evaluate the changes caused in the wheat crop yield components by silicon foliar application. The experiment was conducted in two growing seasons. In the first year, five wheat cultivars (Quartzo, Campo Real, Onix and Fundacep Lineage) were assessed and in the second year four were assessed (Mirante, Campo Real, Horizonte and Quartzo). In both years the crops were subjected to three doses of silicon (0, 3 and 6 L of silicon ha -1). The silicon was applied during the tillering, booting and anthesis stages. The yield components assessed were the number of plants, number of ears, number of fertile tillers, dry matter per plant, hectoliter weight, number of spikelets, number of grains per spike, weight of hundred grains, grain yield and harvest index. Most yield components did not respond to the silicon foliar application. The harvest index (first year) and the number of tillers (second year) however presented a quadratic relationship with the supply of silicon. The remaining differences were attributed to variations among the wheat cultivars.