Plumbagin inhibits the growth, metastasis, and invasion of prostate cancer (PCa). However, its lower bioavailability limits biopharmaceutical properties due to insolubility in water. Prostate-specific membrane antigen (PSMA) aptamer-targeted nanoparticles (NPs) significantly enhanced cytotoxicity in prostate epithelial cells. This study aimed to investigate the effects of plumbagin-loaded prostate-specific membrane antigen (PSMA) aptamer-targeted poly D,L-lactic-co-glycolic acid-b-polyethylene glycol (PLGA-PEG) nanoparticles (NPs) on prostate cancer (PCa) in vitro.PLGA-PEG with a terminal carboxylic acid group (PLGA-PEG-COOH) was synthesized, and plumbagin was loaded on PLGA-PEG-COOH NPs using the nanoprecipitation method and characterized by field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), and laser light scattering. The uptake and distribution of plumbagin-NPs in human PCa LNCaP cells were investigated by fluorescent labeling. Subsequently, PSMA antibody-targeted PLGA-PEG-COOH NPs (targeted NPs) were prepared by covalent binding and characterized by x-ray photoelectron spectroscopy. Furthermore, the anticancer activity of plumbagin-loaded, targeted NPs was compared with that of nontargeted NPs in LNCaP cells in vitro.Plumbagin-NPs (diameter of 189.4 ± 30.6 nm and zeta potential of -17.1 ± 3.7 mV) were optimized based on theoretical drug loading of 5% and a ratio of water:acetone of 3:1. During the first 2 hours, the cumulative release rate of the drug was 66.4 ± 8.56%. Moreover, plumbagin-targeted NPs with nitrogen atoms were prepared. The uptake rate was 90% at 0.5 hours for targeted and nontargeted NPs. The IC50 of targeted NPs and nontargeted NPs was 32.59 ± 8.03 μM and 39.02 ± 7.64 μM, respectively.Plumbagin-loaded PSMA aptamer-targeted NPs can be used in targeted chemotherapy against PCa.