Agronomic practices significantly influence the productivity and quality of cotton plant. Present study was undertaken to evaluate the effect of nitrogen and sulfur fertilizer application on the fiber quality of cotton, during the year 2011/2012 and 2012/2013 under Mediterranean environmental conditions. All the treatments were laid in randomized complete block design in factorial arrangement each treatment were replicated thrice. Five rates of nitrogen (0, 60, 120, 180 and 240 kg ha(-1)) and five rates of sulfur (0, 15, 30, 45 and 60 kg ha(-1)) were involved in the experiments. Results of study indicated that increases in the rate of sulfur have negative impact on the quality of the cotton fiber and the highest rate of sulfur fertilizer gave the lowest fiber length compared with the other sulfur rates. On the other hand, the lowest uniformity ratio was observed by applications of sulfur at 30, 45 or 60 kg ha(-1). It was observed that application of sulfur had no significant effect on micronaire and fiber strength. Further, application of 60 to 120 kg N ha(-1) have positive effect on the fiber length and caused 2.7 to 3.4% improvement in fiber lengths in 2012 compared to the treatment without N, while applications of nitrogen at 180 and 240 kg ha(-1) did not provide an additional increase in fiber lengths. Further, it was reported that application of N significantly improved fiber strength, but these differences were not statistically different from the lowest rate of application and the control treatments in both years and averaged across years. On the other hand, the highest values for uniformity ratio was recorded by using 60 to 180 kg N ha(-1) in 2011. On the basis of these observations, it can be recommend that the use of 120 to 180 kg ha(-1) N in terms of fiber length and fiber strength and 30 to 45 kg ha(-1) S, particularly in terms of fiber length and gin turnout in other areas with similar ecologies. Interestingly, the combination of 60 kg ha(-1) N and 15 kg ha(-1) S were the optimal and could be the most beneficial application for achieving the maximum fiber strength in similar ecologies.