Gibberellins have been shown to suppress floral development in mango, thus farmers have used growth retardants, especially paclobutrazol, to inhibit gibberellin biosynthesis, but in many countries such as Brazil, this is the unique registered molecule, which affects sustainability of the mango industry. The objective of this study was to evaluate the effect of metconazole on gibberellin biosynthesis inhibition and carbohydrate accumulation in ‘Palmer’ mango grown in semi-arid conditions. The experiment was accomplished from 2015 to 2017 in an experimental orchard located in Petrolina, Pernambuco, Brazil. The experimental design were randomized blocks with five treatments, five replications and three plants per replication. The treatments consisted of metconazole (0, 0.7, 1.0 or 1.3 g) and paclobutrazol (1.0 g) application per linear meter of plant canopy. According to the results, metconazole efficiently inhibits gibberellin biosynthesis in mango, but it affects AG1 + AG3 (Gibberellic Acid) and AG4 differently. Therefore, metconazole can potentially be used on mango flowering management, but further studies are required to determine specific management practices.