Sweet sorghum is a multi-purpose crop due to the use of all plant parts. The research was carried out under controlled conditions to evaluate the effect of fertilization management on growth, grain yield and yield characteristics of sweet sorghum grown as a second crop in Mediterranean climate conditions. The experiment was carried out two-factor randomized plot trial with 20 treatments combination of 5 nitrogen levels (0, 50, 100, 150, 200 kg N/ha) and 4 phosphorus levels (0, 50, 100, 150 kg P/ ha) with 3 replications. Some properties were investigated in the study such as, plant height, harvest index, thousand grain weight and grain yield per plant and some characteristics related to yield. The results shown that plant height of sweet sorghum increased with increasing N and P levels up to 200 kg N or 150 kg P per hectare, respectively, but increase beyond 100 kg N or P/ha was not found significant in general. Other features related to yield followed almost the same trend. Grain yield per plant of sweet sorghum increased linearly with increasing levels of N and P up to 200 kg N and 150 kg P/ha in both years. The combined application of 150 kg N + 150 kg P/ha produced highest grain yield.