This work presents the results of two N, P, K, S mineral fertilizer trials with wheat (Triticum aestivum L.) carried out at Itapeva, SP, in 1969 and 1971 on Dark Red Latosol soil. The average results observed in these trials show high effects associated to nitrogen (30 kg/ha N increased 118 kg/ha in the production), to phosphorus (30 kg/ha P(2)0(5) incr. 189 kg/ha), and to potassium (15 kg/ha K(2)0 incr. 82 kg/ha). Sulphur increased the production in 11% in relation to the treatment without fertilizer and in 5% in relation to the complete mineral fertilizer. An economic study of NPK wheat fertilizing was drawn with the data of the experiments.