The present invention provides an aqueous effervescent liquid cleaning composition which upon contact with water provides effervescent action, and which comprises at least 5% wt of a surfactant and a dissolved gas in a sufficient amount to provide the effervescent action, said gas having a higher solubility in an aqueous surfactant-containing composition than in water. It has been found that this composition is easy to produce at affordable cost and gives consumer perceivable benefits.