Acquiring high quality in sweet cherry production is of great importance. Plant growth regulators have been used to increase yield and quality in the production of sweet cherries. Brassinosteroids, a relatively new group of plant growth regulators, have been found with interesting results on plant growth and development. This research was carried out to evaluate the role of brassinosteroids and gibberellins in development of fruit quality and occurrence of physiological disorders in '0900 Ziraat' sweet cherry. Gibberellic acid (GA(3)) and 22S, 23S-homobrassinolide were applied with a sprayer at full bloom and at the beginning of fruit development for a 2-year period. GA(3) was applied in concentrations of 25, 50, and 100 mg l(-1) and 22S, 23S-homobrassinolide was applied in concentrations of 0.05, 0.1, and 0.5 mg l(-1). A combined application of 100 mg l(-1) GA3 + 0.1 mg l(-1) 22S, 23S-homobrassinolide was also applied. Plant growth regulator applications mainly caused an increase in fruit weight and flesh to seed ration, and a decrease in fruit length. The effect was mainly due to gibberellin. Both Total soluble solids and titratable acidity were affected by the hormones and the seasons. Neither growth regulators had an influence on occurrence of the physiological disorders. They were at a lesser level in the second seasons.