Observations of steady nonaxisymmetric chemical wave fronts are reported for upward propagation in iodate-arsenous acid solutions within vertical capillary tubes. These observations confirm a recent prediction of hydrodynamic stability theory that the onset of convection in such fronts should be nonaxisymmetric. The nonaxisymmetric waveform reflects the presence of a single convective roll in the vicinity of the moving front. © 1994 American Chemical Society.