The effects of granulated or ground fertilizer mixture (at two levels: 12:43:25 or 24:86:50 kg/ha of N, P2O5, K2O) were compared with untreated plots in different types of soils in the State of São Paulo (Brazil). Results of ten such experiments showed that in the clay soils, the fertilizer increased significantly the yield, weight of boll and seeds, lint percentages and lint index. In sandy soils the effect of fertilizer on cotton yield was less pronounced, and lint percentage was the only characteristic of the product that was influenced by the application of fertilizer. In general, both granulated or ground fertilizers influenced similarly the development and the yield of cotton plants.