Water solubility of curcumin is increased by PEG in ultrasound medium. Different PEG-curcumin complexes were prepared with and without using ultrasound at 25 degrees C. Curcumin concentrations of complexes were determined by UV. The surface charges of PEG-curcumin complexes were investigated by zeta measurements. Critical aggregate concentrations were determined from both UV and zeta potential measurements. Complexes prepared by ultrasound were found to be more compact and homogenous in both size and charge distribution and they also carried more curcumin. Antioxidant capacity of the complexes, determined by DPPH and FRAP methods, were higher than the capacity of curcumin itself.