In this study, the optimal conditions for spray drying of the extract made from flesh and peel of red pitaya were tested using the central composite design (CCD). The response surface methodology was used to evaluate the effect of inlet air drying temperature (145 – 155°C) and concentration of maltodextrin (13-17% w/w) on the physicochemical properties of the powder. The regression models accurately predicted the retention of betacyanin (R²=0.94) and total phenolic (R²=0.95). The optimal conditions for spray drying were determined as inlet air drying temperature at 148  and 14.62% maltodextrin. Under these conditions, the spray-dried powder achieved retention of betacyanin of 68.04% and retention of total phenolic of 84.17%. The optimized sample achieved a moisture content of 4.41%, the water activity of 0.39, and the water solubility index of 97.41%.