A boundary-element method (BEM) has been developed to investigate the nonlinear evolution of the surface of liquid jets injected from circular orifices. The current treatment focuses on the low-speed jet in which liquid viscosity and gas-phase pressure interactions are of minor importance. The model properly reflects both the presence of the orifice as well as the internal flow geometry. The model has been validated against nonlinear droplet oscillation calculations of other researchers. Results are presented fro flows within the dripping and Rayleigh breakup regimes.