Some of the most economically damaging diseases of cultivated rice are caused by pathogenic fungi. They cause major losses of crop and crop yield. To identify an alternative method of combating these fungi that avoids the use of fungicides, this study investigated the antagonistic activity of the acid-resistant, plant growth promoting bacterium, Rhodopseudomonas palustris KTSSR54 and its bioactive compounds. Exopolymeric substances (EPS), lipopeptides and photo-pigments extracted from strain KTSSR54 showed antifungal activity against three rice fungal pathogens (Bipolaris oryzae NPT0508, Curvularia lunata SPB0627 and Magnaporthe oryzae PTRC63). Among the antifungal extracts, EPS most effectively controlled all tested fungal pathogens. Its minimum inhibitory concentration (MIC) values ranged from 3.75 to 30 mg/ml. Living cells of KTSSR54 and its EPS altered abnormal mycelia of all tested rice fungal pathogens, in the form of wilting and swelling, respectively. They displayed significant activity against all tested fungi to increase rice seed germination percentage. However, EPS at the minimum fungicidal concentration (MFC) showed phytotoxicity toward rice seeds and damaged seedling vigor. Otherwise, infected rice leaf showed no sign of disease symptoms after most treatments involving with live KTSSR54 cells or EPS. Soil pot experiments demonstrated that inoculation with strain KTSSR54 (roughly 10⁸ cells/ml), followed by treatment with EPS at . MIC or MIC could protect infected rice from fungal pathogens. The yield loss from 100-grain weight was roughly 2.5 times less than the loss from all uninoculated KTSSR54 sets. Acid-resistant strain KTSSR54 and its EPS have great potential as biocontrol agents for controlling rice fungal pathogens and could be applied in paddy fields, particularly on acidic soil.