(57) A composition comprising a mixture of anionic surfactants, of the type alkylaryl sulfonates, alkansulfonates, alkyl- ethoxysulfonates, non-ionic surfactants, of the type oxyethylene polycondensates of alkanolamides of fatty acids, alcohols, alkylphenols, and solvents of the type alcohols, glycols, glycol-ethers and ketones having a low molecular weight. The ratio of anionic to non-ionic surfactants in the said composition is comprised in the range between 10 : 1 to 70: 1, with a total amount of active substances in the composition ranging between 60 to 75%. The composition is dissolved in water at the ambient temperature in a short time, such as a few minutes, by simple manual shaking, providing a ready to use liquid detergent with a pH between 6,5 to 7,5. In order to obtain a diluted product having a sufficiently high viscosity, high molecular weight oxyethylene homopolymers may be incorporated in the composition, or the composition may be additivated, upon the dilution thereof, with suitable viscosity-enhancing materials, such as poly-acrylic acids, common electrolytes such as alkaline chlorides and sulfates, and alkanolamides of fatty acids.