Introduction: POULTRY production faces significant challenges from multi-drug resistant (MDR) bacterial arthritis, marked by severe clinical symptoms and the failure of conventional antimicrobial treatments due to alarming resistance. Aim: This study investigated novel green-synthesized lycopene nanoparticles as a therapeutic alternative to combat these issues. Methodology: Forty-two broiler chickens, aged between 3 and 8 weeks, exhibiting arthritis symptoms, were collected from various flocks within Sharkia Governorate. Results: We identified key bacterial pathogens including E. coli, S. aureus, Salmonella spp., Pseudomonas spp., and Streptococcus species from severe arthritis cases in broilers. These isolates exhibited extensive MDR profiles with high Multiple Antibiotic Resistance (MAR) indices (0.5-1) and notably included 100% colistin resistance in Salmonella spp.. Against these highly resistant isolates, lycopene nanoparticles demonstrated potent antimicrobial and anti-biofilm efficacy. Minimum Inhibitory Concentrations (MICs) ranged from 0.1875 to 4 μg/mL across the tested strains, indicating high potency. Notably, Pseudomonas spp., with the highest MAR index, was most sensitive (MIC 0.1875 μg/mL), while S. aureus also showed high sensitivity (MIC 0.5 μg/mL) and produced the largest inhibition zone (30.00 ± 3.41 mm). This potent activity contrasts sharply with the observed resistance to conventional antibiotics, highlighting the nanoparticles' ability to overcome resistance mechanisms. Furthermore, LNPs effectively disrupted bacterial biofilms dose-dependently. Quantitative assessment (crystal violet staining) revealed significant biomass reduction, highly relevant for persistent infections. Conclusion:This study highlights novel green-synthesized lycopene nanoparticles as a promising agent for bacterial arthritis, effective against MDR pathogens and biofilms, offering a sustainable, natural-extract-based alternative where conventional antibiotic therapies are compromised.