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The effects of upstream conditions, such as nozzle and entrance shapes, on external flow characteristics continue to challenge fuel injection modeling efforts, particularly in the case of high-pressure diesel sprays. In this research, flow details were investigated both experimentally and numerically in a fuel injector nozzle orifice using an integrated approach. Calculations using the SIMPLE algorithm were first performed for the scaled-up experimental nozzles with various length to diameter ratios (L/d). Measurements of internal flow velocities for these nozzles were made by laser Doppler velocimetry in order to verify the computational results. Mean and fluctuating velocities and discharge coefficients were obtained at various Reynolds numbers. The mean turbulence intensity and turbulent kinetic energy for a sharp inlet nozzle were generally higher than for a round inlet nozzle, except for the near-wall region beginning at about one nozzle diameter from the entrance.