The objective of this study was to investigate the effects of the geometric parameters of a pressure-swirl duplex nozzle (dual orifice) on the spray characteristics of Jet A-1 fuel. Two pilot nozzles with different shapes and two main nozzles with different shapes were tested. The spray characteristics were analyzed by employing laser diagnostic techniques, namely a phase Doppler particle analyzer (PDPA) and planer laser sheet imaging. Atomizer performance including flowrate, discharge coefficient, spray structure, resulting droplet size, and velocity distribution were analyzed. The results compared the atomization characteristics under various injection conditions and nozzle geometry that showed considerable major alteration in spray characteristics. This type of atomizers is mainly used as fuel injectors in gas turbine combustors. Hence, the results could be of interest to the combustion society, although this research is entirely cold flow.