The present experiment was conducted on six-years-old “Keitt" mango trees at El-Bostan region, El-Behira governorate, Egypt to study the effect of 4-chlorophenoxyacetic acid (4-CPA) and brassinosteriods (BR) on fruit set, yield and quality of “Keitt" mangos. The following seven treatments were used, control, brassinoloide at 1 mg/L, brassinoloide at 2 mg/L, 4-chlorophenoxyacetic acid at 10 mg/L, 4-chlorophenoxyacetic acid at 20 mg/L, brassinoloide at 1 mg/L + 4-chlorophenoxyacetic acid at 10 mg/L and brassinoloide at 2 mg/L + 4-chlorophenoxyacetic acid at 20 mg/L. The treatments were applied twice at full bloom and after fruit set with ten days. The results showed that pre-harvest application of 2 mg/L brassinoloide increased fruit set, fruit retention, yield, average fruit weight, average fruit size and ascorbic acid. Pre-harvest applications of 4-chlorophenoxyacetic acid either at 10 mg/L or 20 mg/L increased fruit set, retention, yield, fruit weight, size, fruit firmness and ascorbic acid. The formulation containing 4-chlorophenoxyacetic acid plus brassinoloide either at low concentration or high concentration enhanced fruit set, yield, firmness, fruit physical and chemical quality of “Keitt" mangos fruit.