Starting from a simple dispersion relation for negative index materials and a heuristic nonlinear Klein–Gordon-type extension, we derive the evolution equations for the envelopes of beams and spatiotemporal pulses in nonlinear dispersive negative index media. Using existing numerical methods, based on fast Fourier–Bessel transforms, we study the stability of the solitary wave solutions. Nonlinearity and dispersion management are then incorporated to find stable solutions of the underlying partial differential equations.