BACKGROUND: Meloidogyne incognita is a highly damaging pathogenic nematode that causes significant annual economic losses. Therefore, the development of reliable biological control agents against M. incognita is imperative. The Bacillus velezensis RKN1111 strain, isolated from inter-root soil, demonstrates the ability to directly kill M. incognita. In this study, we investigated the effect of RKN1111 in inducing resistance to M. incognita in Cucumis sativus and examined changes in the content of immune-responsive substances in the induction-treated cucumber plants. RESULT: The RKN1111 treatment reduced the number of root galls in infected cucumbers, with a maximum reduction of 78.19%. RKN1111 stably colonized cucumber roots, reaching 3.65 × 10 CONCLUSION: RKN1111 has been demonstrated to stably colonize cucumber root systems and defend against M. incognita infestation by inducing systemic resistance in the host plant. Additionally, RKN1111 elevated the levels of immune-responsive substances in cucumber plants. RKN1111 has great potential for application in the integrated pest management of M. incognita. © 2025 Society of Chemical Industry.