Abstract: This review surveyssome capillary flows capable of stretching fluid interfaces downto the micrometric dimension and below. These types of flows havebecome the basis for attractive techniques to produce monodispersemicro- and nanoparticles with either simple or core-shellstructure (micro- and nanocapsules, coaxial nanofibers, and hollownanofibers). These techniques enable precise control on theparticle mean size. We also review the basic physics of the flowand the dimensionless parameters that govern these capillaryflows. Some examples of the types of particles produced by a fewdevices are also presented.