This article describes the design, development and testing of a trunk injection machine. The machine comprised of an injection apparatus, hydraulic system and 200-litre storage tank mounted on a mini-tractor. Experiments were conducted to test injection effectiveness test, time and motion study (TMS) and field trial. The injection effectiveness test using 0.1% eosin dye on the healthy palms revealed that the machine was able to spread the dye to more than 60% coverage on the vertical (X) and horizontal (Y) axes, and up to 65 cm upwards on the longitudinal axis (Z). Results recommended to have two injections per palm for a better coverage profile. TMS revealed that the machine was able to treat about 37 palms per day with the injection cost of about RM 3.15 per palm. Study on 2088 Ganoderma-infected palms in an estate showed that 95.6% of the infected palms were still standing after one year treatment with Hexaconazole. The cost-effectiveness was calculated at RM 1.02 per palm over five-year of economic life. With the performance and cost of the machine, it is recommended that this machine is suitable to be used to treat palms infected with basal stem rot disease (BSR).