The efficacy of entomopathogenic nematodes (EPNs), Steinernema feltiae and Heterorhabditis bacteriophora, for controlling Frankliniella occidentalis (Thysanoptera: Thripidae, Pergande, 1895) in nectarine orchards, was evaluated, alongside their potential impact on honeybees (Apis mellifera, Hymenoptera: Apidae, Linnaeus, 1785). Field trials revealed that S. feltiae significantly reduced thrips populations and fruit damage compared to the control, while H. bacteriophora showed no significant effect. The reduction in feeding scars on fruits from S. feltiae–treated trees underscores its potential as a sustainable biocontrol agent. However, laboratory bioassays indicated that another EPN, Steinernema carpocapsae, induced delayed mortality in honeybees under high-exposure conditions, pinpointing the need for careful application to minimize risks to pollinators. These findings demonstrate the potential of S. feltiae for integrated pest management (IPM) in nectarine cultivation while emphasizing the importance of species-specific selection and pollinator safety. Future research should focus on optimizing application methods, understanding environmental influences on EPN efficacy, and assessing long-term impacts on pollinator health to ensure sustainable pest management practices.