We report the first example of a successful preparation of a microporous organic polymer within the droplet phase of an inverse non-aqueous miniemulsion. Stable nanoparticles with enhanced specific surface area could be obtained despite the harsh conditions regarding reaction temperature (180 degrees C) and time (72 h) needed for building melamine-based Schiff base networks. Our new flexible method can in principle be applied to other water-sensitive protocols suitable for the bulk synthesis of MOPs that are based on Friedel-Crafts, Sonogashira-Hagihara or Yamamoto chemistry.