Abstract: Polyhydroxyalkanoates (PHAs) are groups of biodegradable thermoplastic polymers synthesized by various microorganisms. PHA producing bacteria accumulate PHA in their cells as carbon and energy storage compounds. This research objective was to acquire a strain of PHA producing bacterium isolated from rice barn. Rice barn samples were collected from rice mills at Nakhon Ratchasima Province, Thailand. Bacterial PHA production was isolated on Tryptic Soy Agar (TSA), cultured on complex and minimal medium agar and then screened on minimal medium agar supplemented with Nile Red. PHA accumulation in bacterial cells was detected by Transmission Electron Microscopy (TEM) and fluorescent microscopy on samples stained with Nile Blue A. The 40 of 214 isolates produce PHAs in their cell at rates from 5.1-76%. Bacterial strain RB36 produced PHAs in as much as 76% of cell areas. The strain was sequenced based on 16S ribosomal RNA gene and then submitted in GenBank with Accession No. MG745383 and identified as 99.8-100% similarity to enter ococcus faecium. This is the first report of a potential strain of PHAs-producing bacterium isolated from rice barn from Thailand.