A novel strain of Photorhabdus luminescens ZMI isolated from nematode larvae Heterorhabditis sp. was shown to produce antibiotic complexes with antibacterial and antifungal activities. The antibiotic complexes secreted extracellularly and intracellularly were separated into individual components. Comparison of their properties with the databases for biologically active compounds suggested that component A was identical to 3,5-dihydroxy-4-isopropylstilbene, components B and H belonged to anthraquinone derivatives, component C secreted only extracellularly was likely a novel antibiotic.