A new design of a confined impinging jet microreactor has been applied for continuous-flow syntheses of metal chalcogenide nanomaterials. The microjet reactor is an automated, flexible, scalable, and thus industrially viable technology allowing a strict control over process parameters for the design of materials with tunable properties. Due to the short mixing times in the mu s to ms range, crystallite nucleation and crystal growth are well separated and enable concentration-limited particle growth and thus nanoparticle synthesis. The first approaches on the microjet reactor setup presented here were focused on the synthesis of nanocrystalline Ta-doped tin dioxides and cadmium sulfide nanoparticles. The nanomaterials were characterized by a number of methods like powder X-ray diffraction and conductivity measurements.