Curcumin, a yellow, natural dye found in Curcuma longa has been extensively studied due to its biological activity (anticancer, anti-inflammatory, antioxidant among others). Although its antimicrobial properties have been well characterized, large scale use of curcumin in foodstuff is hindered by its low water solubility. Although the mechanism of the antimicrobial activity of curcumin is subject of debate, the existence of methoxyl and hydroxyl groups is believed to be responsible for the antimicrobial activity. It is known that polyvinylpyrrolidone (PVP) and curcumin complex to form nanoparticles under suitable conditions. However, it remains to be investigated if the interactions between PVP and curcumin affects the antimicrobial properties of the later. The objective of this work was to produce PVP-curcumin nanoparticles and investigate their antimicrobial activity against Gram positive (S. aureus (IAL1875) and B. cereus (IAL550)) and Gram negative (E. coli (IAL339) and P. aeruginosa (IAL2081)) microorganisms. Nanoparticles were lyophilized and characterized providing the following results: average particles size of 100 nm (Dynamic Light Scattering), spherical morphology (Transmission Electron Microscopy), curcumin encapsulation efficiency of (96 ± 2) % (UV-Vis Spectroscopy). Differential Scanning Calorimetry, Infrared Spectroscopy and X-rays Diffraction demonstrated that curcumin was distributed inside the particles in an amorphous state strongly indicating an efficient entrapment of curcumin inside the nanoparticles. Minimum Inhibitory Concentration results for S. aureus, E. coli, B. cereus, and P. aeruginosa were as follows (µg/mL): 500, 250, 125, 250 for pristine curcumin. PVP-curcumin nanoparticles were not able to inhibit microbial growth even in 1,000 µg/mL. This can be attributed to the fact that curcumin is complexed to PVP decreased their antimicrobial activity, means that curcumin must be free to interact with cell membranes of microorganisms. This observation was confirmed by infrared spectroscopy and Nuclear Magnetic Resonance hydrogen.