There were no significant interaction between particle sizes of perlite and concentrations of nutrient solution on the growth and yield variables except root length (Table 3). All the growth parameters were greater in carrot plants grown in 0.6 mm than other perlite sizes supplied with five concentrations of nutrient solution. Highest dry weight of leaves was recorded from plants grown with 100% of nutrient solution in 0.6 mm perlite which was attributed by maximum leaf length and higher number of leaves. Significantly higher root yield (146.3 g fresh weight per plant) attributed by longer and wider carrots were harvested from plants grown in the 0.6 mm perlite with 100% nutrient solution. It is evident that carrots grown in 0.6 mm with 100% nutrient solution produced about 30, 58 and 43% greater root yield than those grown in 1.2, 2.5, and 5.0 mm perlite, respectively with the same concentration. Although carrot plants grown with 200% nutrient solution in 1.2 and 2.5 mm perlite produced significantly similar dry matter as with 100% nutrient solution in 0.6 mm, but root yield was not improved greatly in perlite particle size higher than 0.6 mm. Therefore, 100% nutrient solution was found to be optimal for maximize carrot root yield in hydroponics