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The present study focuses on the causes of dissimilarity in the flow structures of sprays produced by different holes of the same direct injection high-pressure diesel nozzle. To assess the effect of nozzle geometry on the transient spray structure, photographs of the spray plumes produced by VCO, mini-sac and reduced sac nozzles at different delays from the start of injection were acquired. Injected fuel volume, feeding pressure, injection duration, spray penetration and cone angle were measured for all the investigated nozzles. A statistical analysis of the acquired images and data showed that sprays from the same hole were highly repeatable even with clear hole-to-hole variation of the spray structure. In particular, for the three investigated nozzle geometries the effect of nozzle flow rate, hole inlet and outlet diameter, needle geometry and working time under engine conditions were investigated. Microscope pictures of the nozzle holes were also acquired.