The creole potato (Solanum phureja Juz et Buk) is planted in an important area of Colombia. It is accepted by the people due to its nutritive value and culinary qualities and has a good export potential to Europe, Japan. United States and Canada. Nitrogen and Sulphur play an important role in yield and quality. Therefore the present research was developed, having as objectives to determine the effect of nitrogen and sulphur applications on tuber yield, quality and protein content, the establishment of the most adequate N/S relationship in petioles and to perform an economic evaluation of the results. The research was developed on an Hapludand soil at 2850 m.a.s.L, 11°C mean temperature, 85% relative humidity. 13% organic matter content, alofane presence, median to low available sulphur content. loamy sand texture, pH 4.85 and an adecuate Ca:Mg:K relationship. A completely randomized block design in factorial arrangement was utilized. Nitrogen levels employed were 0-40-80-120 Kg N/ha and sulphur levels were 0-20-40-60 Kg S/ha. The sources used were amonion nitrate with 30% nitrogen and calcium sulphate with 16% sulphur. The results showed a significative response in total yield and tuber size. The highest yield, compared with the check (1.8 t/ha) was 24 t/ha. Protein content was found to be related to an adecuate quantity and relationship of nitrogen and sulphur fertilization. With the use of 120 Kg M/ha and 20 Kg S/ha the tuber protein of 6% was obtained, while the check tuber protein reached only 3.5%. The best M/S relationship in the petiole was 16:1. Taking intoaccountthe potato price and the cost of fertilizers each peso ($) inverted in nitrogen and sulphur returned $ 87.