Abstract: Background and Objectives: Tuber of Myrmecodia tuberosa Jack (Rubiaceae) has been widely used as herbal remedy in Indonesia. This research aimed to evaluate the effects of M. tuberosa Jack on quorum-sensing related pathogenicity of Pseudomonas aeruginosa and Staphylococcus aureus. Material and Methods: Following delipidation with petroleum ether, pulverized tuber was macerated in methanol. After evaporation to obtain methanol extract, liquid-liquid partition was perform on the extract to yield hexane, ethyl acetate and water fractions. The extract and fractions were screened for the effects on the planktonic growth of P. aeruginosa and S. aureus. Inhibition of pigment production was observed on cetrimide Agar following sample treatment on Pseudomonas aeruginosa. Samples were prepared as 2-0.0625 mg mL–1 concentration. The effects on swimming, swarming and twitching motility of Pseudomonas aeruginosa PAO1 following sample application were observed. All experiments were done in triplicate. Results: Results showed that the ethyl acetate fraction caused a prominent effect on quorum sensing inhibition which might explain its biofilm inhibition effect on P. aeruginosa. Significant inhibitory effect in a concentration dependent manner towards pigment production inhibitor and motilities were observed over control. Conclusion: Despite being active as planktonic growth inhibitor towards S. aureus and P. aeruginosa, M. tuberosa ethyl acetate fraction is recommended to be investigated further as anti-infective against P. aeruginosa.