Static flow rate and initial cone angle of high-pressure swirl injector nozzles were characterized through measurements and computations as a preliminary optimization process of nozzle design. Prototype injectors were fabricated by modifying commercial multipoint injection (MPI) nozzles. Measurements of static flow rate were compared with the computations, and the agreements were satisfactory in values and tendencies with respect to the nozzle geometry and the needle lift. Initial cone angle was calculated and compared with measurements by the direct photographic imaging method. It could be predicted satisfactorily by introducing an adequate correction factor. Considering these cross-checking for a validation of the computational model, a parametric study was carried out to predict the flow rate and the initial cone angle with respect to selected design parameters.