Miniemulsion is an innovative method to obtain, already at room temperature, crystalline inorganic materials by exploiting a reaction occurring inside the confined space of independent nanometric-sized droplets. Despite being a promising technique, to the best of our knowledge no systematic study on the crystallization phenomena under miniemulsion conditions has been carried out yet. In this regard, we performed by Small-Angle X-ray Scattering (SAXS) an in-situ and time-resolved investigation of the crystallization process of ZnS synthetized by inverse miniemulsion . The experimental setup for this experiment was composed of a reactor equipped with a probe-type sonicator, connected with a continuous flow equipment. While the reaction was carried out, the reaction mixture was continuously flowed thought a homemade measurement cell mounted in the SAXS beamline of the synchrotron facility Elettra (Trieste), to follow the structural and morphological evolution of the system in real-time. The obtained SAXS profiles were then fitted in order to get an insight of the dimension and the number of the formed particles with time. Moreover, the same setup was employed to investigate the miniemulsion without the presence of the ZnS precursors, and the effect of the surfactant concentration on the synthesis.