Roads in Nigeria and like any other developing country are hugely plague with deterioration and damage due to excessive traffic beyond design load, environmental conditions and their interactions as well as low budgetary allocation for routine/preventive maintenance. In order to address the problems, researchers/practitioners in the highway community have engaged in the use of admixtures and waste material to enhance the properties of paving materials while reducing the cost of production. This study investigates the suitability of Gum Arabic (GA) also known as acacia gum to be used as bitumen modifier in Hot Mix Asphalt (HMA). GA is a natural material consisting of hardened sap of various species of acacia. Its glue or binder properties makes it suitable for use as a bitumen modifier. In order to evaluate its performance in asphalt concrete mix, 0%, 2.5%, 5%, 7.5% and 10% GA was added at bitumen content of 4.5%, 5.5%, 6.5% and 7.5%. Marshall mix design method was used to examine the effect of the modifier on the Marshall indices and volumetric properties of HMA. The study revealed that HMA mixes prepared with 2.5% of the modifier by weight of binder (bitumen) performs best and satisfy all the requirements stipulated by the Nigerian General Specifications for Roads and Bridges (2016) for use as wearing course of flexible pavements.