A model of a reflective bistable twisted nematic liquid crystal display was studied by detailed numerical simulation. The optimized modes of a 5 μm reflective bistable twisted nematic liquid crystal were determined by the parameter space method. We have shown that large wavelength dispersion in the reflection coefficient of such displays cause the optimal mode to have a small value of dΔn, around 0.2 μm. By using a quarter-wave plate compensation film the optimized modes can have a dΔn value of around 0.4 μm. Numerical simulations show a wide viewing angle of up to ±60° for both types of reflective bistable twisted nematic liquid crystal display.