Honey produced by stingless bee is commonly known as Kelulut honey. Honey is frequently heated to purify, filter, and permit packing in order to inhibit the growth of microbes. However, heating could increase the amount of the potentially cancer-causing substance hydroxymethylfurfural (HMF) in honey and will reduce the physicochemical and nutritional attributes due to its heat sensitivity. Hence, ultrasound which is a non- thermal processing was chosen as an alternative method to minimize the quality loss during the processing of Kelulut honey. The purpose of this study was to investigate the effect of ultrasound processing on the quality of Kelulut honey. The ultrasound processing was conducted at five different amplitudes (20, 40, 60, 80, and 100%) and three different treatment times (5, 10 and 15 minutes). Kelulut honey samples were analysed for total soluble solids, water activity, moisture content, pH, and the amount of HMF. Conventional heating was conducted at 60 °C for 30 minutes as a comparison. The results showed that the ultrasound processing increased the total soluble solids of Kelulut honey from 65.32 °Brix to 73.00 °Brix and the pH value from 2.97 to 3.62. Ultrasound processing also reduced the moisture content of Kelulut honey from 33.08% to 25.40% and water activity from 0.8188 to 0.7580. For the HMF value, ultrasound processing slowed down the formation of HMF in Kelulut honey compared to conventional heating as it only increased from 14.33 mg/kg to 34.44 mg/kg. According to these findings, the application of ultrasounds at 20% for 5 minutes was the most suitable combination of amplitude and treatment time as it could minimize the increase in HMF. Thus, it can be concluded that ultrasound processing can be used as an alternative method to the producers in providing minimally-processed Kelulut honey and maintaining the quality of honey.