Laser reflectometry has been used for the first time as an in situ real-time monitor of the dissolution of the (0 0 1) face of KClO3 crystals into aqueous solution. During the dissolution process the reflected light was subject to constructive and destructive interference caused by the movement of crystal boundaries. This produced Fabry-Perot oscillations similar to the widely exploited phenomenon used in the laser reflectometry-based metrology of semiconductor surfaces. The method is adapted and theoretical fits to the observed data are presented. The quality of the data allows dissolution rates of 100 nm s(-1) to be measured accurately. Data gained by this method was used to verify the concentration dependence of the dissolution rate and confirm it as a diffusion-controlled mechanism. The hydrodynamic radius of the diffusing ions was found to be 0.224 nm, in agreement with literature values. The potential of laser reflectometry for use as an effective probe sensitive to changes in crystal surface morphology during dissolution has also been demonstrated.