This study was conducted to screen the endophytic bacteria as a biological control agent (BCA) against Ganoderma boninense. A total of 581 endophytic bacteria were successfully isolated from symptomless oil palm root tissues at Teluk Intan, Perak, Malaysia. Three endophytic bacteria, Pseudomonas aeruginosa GanoEB1, Burkholderia cepacia GanoEB2, and Pseudomonas syringae GanoEB3 were found to have a potential as BCA based on their percentage inhibition of radial growth (PIRG) in dual culture and culture filtrate tests. Two nursery trials were conducted to evaluate the capability of these bacteria to suppress Ganoderma disease in oil palm seedlings that were artificially infected with G. boninense using rubber wood block (RWB) sitting technique. The percentage of disease incidence (DI), severity of foliar symptoms (SFS) and dead seedlings were used as the assessment tools. As a result, DI and SFS have developed much slower in the seedlings that were pre-treated with bacteria compared to untreated seedlings. After 6 months of inoculation, Ganoderma disease incidence was reduced from 62-75% in the seedlings treated with P. aeruginosa GanoEB1, followed by B. cepacia GanoEB2 (31-59%) and P. syringae GanoEB3 (30-31%). Among these three endophytic bacteria, P. aeruginosa GanoEB1 was the most effective in controlling Ganoderma disease and the dead seedlings were in the range of 13.3-26.7%, followed by B. cepacia GanoEB2 (33.3% for both trials) and P. syringae GanoEB3 (33.3-40.0%) compared to untreated seedlings at 60% for both trials. A field study needs to be conducted to verify their effectiveness in controlling Ganoderma in oil palm.