Abstract: The present invention relates to self adhesive hard surface cleaning blocks, and their use. It is an object of the present invention to provide a detergent block that can be easily positioned onto a hard surface; even a wet surface. It is a further object of the invention to provide a detergent block that rinses away in a number of flushes, and does not leave behind any residue that cannot be easily removed with e.g. a toilet brush. We have found that a hard surface cleaning block comprising surfactants forming a liquid crystalline phase upon contact with water meet the objects of the invention.