Boundary integral method and parallel processing techniques are used to simulate the motion and break-up of deformable particles (including drops and bubbles) encountered in a variety of biological and industrial situations. Particles are of a newtonian fluid, and are bounded by interfaces with generalized mechanical properties. Analysis is performed in two- and three-dimensions, for individual particles, a periodic lattice of particles, and a random dispersion. The main objectives of the research are to delineate the significance of interfacial properties on the motion and deformation of particles, compute the magnitude of interfacial tensions developing during deformations, establish criteria for permanent deformations and break-up, and study the rheological properties of dilute and concentrated suspensions. The research is conducted through numerical computations which are based on asymptotic methods and advanced implementations of boundary integral methods. A substantial part of the numerical effort is devoted towards developing efficient techniques of coupling the flow inside and outside a particle and the deformation of the interfaces. The proposed field of research is relevant to bioengineering and chemical manufacturing processing, as well as to high performance computing.//