The current study aimed to evaluate effects of four levels (0, 2, 4 and 6 % of diet) of soybean lecithin in the isoproteic and isoenergitic (50% protein and 18.5 kj/g) diets on growth performance, feed utilization and hematological parameters of juvenile sobaity seabream (Sparidentex hasta) with initial weight of 37.9±0.16 g. At the end of 56 days of feeding trial, results showed that growth performance increased with increasing dietary lecithin from 0 to 6%; however, growth decreased with increasing dietary lecithin from 6 to 9%. Fish fed the 6% lecithin diet had the highest final weight (86.19±2.99 g), weight gain (48.41±3.6 g) and specific growth rate (1.47±0.07) (p<0.05). Survival rate, feed conversion and protein efficiency ratios as well as hematological parameters were not changed in different groups (p>0.05). The results of this research showed that, inclusion of 6% of soybean lecithin in diet for sobaity seabream juvenile is optimum for improving growth performance parameters in this species.