This study aims to assess the effect of Eurycoma longifolia aqueous extract on chilled and cryopreserved quality of bull sperm. Semen samples were obtained from four Simmental-Brangus. Each sample was divided into two fractions: the first fraction was used for chilling the semen, and the second fraction was used for the freezing process. Both fractions were extended with Tris-egg yolk extender supplemented with 0.0, 0.25, 0.5, 1.0, 2.5, 5.0, and 7.5 mg/ml Eurycoma longifolia aqueous extract. The diluted chilled fraction was chilled at 5 °C for 6 days, whereas the frozen-thawed fraction was frozen in liquid nitrogen. Data revealed that 1 mg/ml E. longifolia aqueous extract yielded significantly (p