The effect of processing parameters (homogenization time, stirring speed and oil:water ratio) of β-carotene nanoemulsions (stearic acid as oil phase) was studied via a central composite design (CCD) by response surface methodology (RSM). Particle size and nanoemulsions stability (β-carotene concentration, color and antioxidant activity) stored for 21 days at 25 and 4 °C were selected as response variables. Maximum particle size obtained was 1689.0 nm and minimum particle size was 418.8 nm, which a second order model were adjusted with R2 values of 0.766 and 0.933 at 25 and 4 °C, respectively. The particle size was affected directly by the homogenization time and inversily proportional to stirring speed and oil:water ratio. Parameters as β-carotene concentration and antioxidant activity showed a gradual decrease during storage, showing a great stability those that were stored at 4 ºC. The optimal conditions to produce β-carotene nanoemulsions with minimum particle size were found at 25 °C for homogenization time 5.99 min, 5287 rpm and an oil: water ratio of 0.8:99.2; at 4 °C homogenization time 5.99 min, 8002 rpm and 0.62:99 oil:water ratio.