Aerobic granular sludge (AGS) is a wastewater treatment technology that is known for having unique advantages such as great settling ability, high biomass level, good shock resistance, and able to withstand high organic loadingr at e (OLR) and toxic pollutants. Since studies on AGS development ar e mostly conducted in laboratory scale, the detailed knowledge regarding the pilot scale study is still limited especially for hot and humid tropical climate condition. Therefore, this study focused on the characteristics and performance of AGS cultivated in a pilot-scale bioreactor for hot and humid tropical climate condition, specifically in Malaysia. The formation of AGS as well as biomass concentration were al so investigated during the treatment of real domestic wastewater. From the result, it was found that the highest average diameter of the cultivated mature granuleswas 3.36 mm with a biomass concentration of 12.48 g L −1 after 93 days of operation. The aerobic granular sludge also achieved promising removal rates of 89 %, 75 %, 96 %, and 93 % for COD, phosphate, ammoniacal nitrogen, and total inorganic nitrogen, respectively
