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. The objective of this work was to obtain curcumin microcrystals by the wet milling procedure and evaluate their antimicrobial activity against Gram positive (S. aureus and B. cereus) and Gram negative (E. coli and P. aeruginosa) microorganisms. The micrometric crystals were compared to pristine (in natura) curcumin using the modified agar dilution technique and the minimum inhibitory concentrations (MIC) as well as the inhibition percentage (%) were determined. Results demonstrated that an efficient dispersion system like an Ultraturrax dispersor at 10,000 rpm without any other stabilizer was required to obtain non-agglomerated, micron-sized curcumin crystals. Differential Scanning Calorimetry, Infrared Spectroscopy, X-rays Diffraction and Optical Microscopy showed that no physical or chemical changes other than the particle size occurred after the wet milling procedure. MIC results for S. aureus, E. coli, B. cereus, and P. aeruginosa were as follows (µg/mL): Pristine curcumin: 500, 250, 125, 250; curcumin microcrystals: 250, 125, 125, 125.This means that, except for B. cereus, microcrystals were more effective in inhibiting microbial growth. Optical microscopy demonstrated that, unlike pristine curcumin, microcrystals were homogeneously distributed along the agar. The increase in the antimicrobial activity could be attributed to the high total surface area which increased the effectivity of curcumin. One can conclude that the wet milling is a promising technique to improve the antimicrobial activity of curcumin since it presents low cost and can be easily implemented.