Soluble gas bubbles in a liquid experiencing radial oscillations created by an acoustic field are considered. It is shown that the resonance frequency of large soluble gas bubbles practically coincides with the natural frequency of gas bubbles as determined by the Minnaert formula. In the case of small gas bubbles, the presence of capillary effects and solubility of the gas in the liquid leads to a new resonance frequency that differs from the Minnaert frequency. A simple analytic formula is obtained that relates the resonance frequency of a soluble gas bubble and its radius. (c) 2005 Elsevier Ltd. All rights reserved.