<p>An experimental study was performed to compare the effect of aft-deck in the mixing and acoustic characteristics of a subsonic jet emanating from a serpentine elliptic nozzle. The baseline serpentine nozzle and the one equipped with the aft-deck were both operated at an NPR of 1.6, which corresponded to an exit Mach number of 0.84. The wall pressure distributions highlighted the formation of inherent secondary effects inside the curved passage of the serpentine nozzle, whose distortive influence on the external jet was attenuated by the aft-deck. More importantly, the asymmetric geometry of the baseline serpentine nozzle caused the jet to deflect downward along the plane containing the minor axis of the elliptic exit, which skewed the occurrence of mixing and noise generation towards the lower side of the nozzle. The aft-deck prevented the immediate spreading of the jet on the lower side and caused a relatively more symmetric development of the mixing layer. This, in turn, reflected on the near-field acoustic measurements, which revealed that the presence of aft-deck reduced noise levels on the lower side, while simultaneously increasing the same on the upper side. It was also clear from the velocity profiles that after sufficient downstream distance, the jet emerging from the aft-deck nozzle exhibited better mixing. The far-field noise along the minor plane was asymmetrically distributed for both the nozzles, with lower side noise being greater than that on the upper side for the same directivity angle. Generally, the aft-deck nozzle was marginally noisier than the baseline variant, with the exception of directivity angles ranging from θ = −40° and −70° (negative sign indicates lower side), which corresponds to the side-line region, where the jet’s expansion was obstructed by the aft-deck.</p>