The group-hole nozzle is regarded as a promising instrument to facilitate better fuel atomization and evaporation for direct-injection diesel engine applications. This work, and the accompanying paper present an experimental study of spray, and mixture properties of the group-hole nozzle by, means of the ultraviolet-visible laser absorption-scattering (LAS) imaging technique. In this paper (Part I), study is focused oil the spray, behavior of the group-hole nozzle with close and parallel orifices, in comparison with the conventional single-hole nozzle. Experiments for nonevaporating and evaporating sprays were designed to clarify, the effect of the group-hole nozzle. As a result: (1) Due to the minimization of the nozzle orifice used with nonevaporating sprays, the group-hole nozzle concept displays the potential to produce better fuel atomization and it does not adversely, affect spray spatial distribution. (2) Under evaporation conditions, the peak equivalence ratio of the vapor phase is increased using the group-hole nozzle. Mixture properties (including mass of ambient gas entrained, mass of fuel vapor, and evaporation ratio) can also be improved with the group-hole nozzle, which is helpful in forming a leaner more homogeneous fuel-gas mixture; this is especially evident at high injection pressure. Despite the potential to improve atomization and evaporation using the group-hole nozzle, no significant difference was detected between the two nozzles used in this work. In a second publication (Part II), another two series of group-hole nozzles will be analyzed to investigate the effects of nozzle specifications on spray and mixture properties by extending the LAS technique to a nonaxismmetric spray analysis.