The root-knot nematode (RKNs) Meloidogyne incognita, are a significant biotic factor that negatively impacted both the yield and quality of vegetables. The nematophagous fungus, Purpureocillium lilacinum, is widely regarded as a highly effective biocontrol agent (BCA) for RKNs. To investigated the nematicidal efficacy of P. lilacinum against eggs and second-stage juveniles of M. incognita at varying application durations, this investigation was carried out at the invitro settings of the Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh. The results also revealed that P. lilacinum effectively reduced the survival rates of M. incognita eggs and juveniles in an application time dependent manner. Microscopic examination displayed that the fungi directly invaded the eggs and made contact with the juveniles, demonstrated its parasitic nature against M. incognita. We also found that P. lilacinum effectively suppressed nematode populations and reduced the incidence of root galls. Notably, the application of P. lilacinum significantly stimulated plant growth metrics and biomass, even in the presence of nematode infections. Our research findings suggest that P. lilacinum can be employed as a beneficial biocontrol agent to manage RKNs and to also enhance the development of the vegetables.