A review with some new data. Adding a vibration on a laminar jet for controlled break-up into monodisperse microcapsules is one among different extrusion technologies for encapsulation of cells, microbes, yeast, enzymes and liqs. (Poncelet, 1997). The vibration technol. is based on the principle that a laminar liq. jet breaks up into equally sized droplets by a superimposed vibration. In the late 19th century, Lord Rayleigh theor. analyzed the instability of liq. jets (Rayleigh, 1878). He showed that the frequency for max. instability is related to the velocity of the jet and the nozzle diam. The optimal vibration parameters are easily and quickly detd. in the light of a stroboscope. Once detd., the parameters can be reset in the future, making the process highly reproducible. In this presentation we will show optimal prodn. parameters for beads and capsules including monodispersity parameter for narrow size distributions, we will provide examples of encapsulation of animal cells and org. liqs. in microcapsules and analyze the prerequisites for scale-up strategies of the vibration jet break-up technol. [on SciFinder (R)]