The current research work investigates a twin-jet cross-stream airblast atomizer, which allows radial injection of two opposite liquid jets from a central hub into laterally flowing high-speed air within a surrounding annular region. The aim is to understand the dynamics of the primary breakup process of both jets and spray fluctuations at the immediate exit of the injector. Experiments were performed for a range of aerodynamic Weber number (Weg = 2–40) and momentum flux ratio (MFR = 1–7) that ensured jet-wall interactions leading to liquid films were avoided prior to completion of the jet breakup. High-speed shadowgraph images were captured for time-resolved visualization of the two liquid jets simultaneously and also, separately, for spray droplets immediately downstream of the injector exit. The primary jet breakup images were processed to measure not only the mean jet breakup/penetration length and trajectory within the atomizer, but also fluctuations of breakup/penetration length and initial instability on the liquid-air interfaces. In addition, jet-to-jet variation in the primary breakup process was also examined. The image processing of shadowgraph images of the droplets led to measurement of instantaneous droplet number count and droplet size and velocity distribution, which showed significant temporal variation. In addition, the fluctuations of local liquid mass flux were measured, which was found to be comparable to the mean mass flux. The results highlight the upstream influence of jet breakup unsteadiness on the downstream spatio-temporal fluctuations of spray characteristics. © 2019 by Begell House, Inc.