Acne vulgaris is a skin disease that affects 79%-95% of the adolescent population in western societies. The bacterial agent Propionibacterium acnes may colonize sebum-rich follicles, and Staphylococcus aureus and Staphylococcus epidermidis can be isolated from skin lesions. Hundreds of medicinal plant extracts and oils have been investigated in vitro for antibacterial activity against acne vulgaris. However, new approaches are under development for topical delivery of herbal oils as there is a need for novel and more efficient drug-delivery systems. Considering the attractive properties and advantages of chitosan nanoparticles (NPs), we aimed to develop coconut oil-loaded chitosan NPs and to identify their antibacterial effects, antibiofilm properties, and toxicity profile.