A method and arrangement for monitoring the supply of cleaning liquid from a cleaning line to a milking system, where the milking system includes at least two milking stations and milk conduits, and the cleaning line includes supply conduits connectable to the milk conduits at the milking stations and arranged to apportion cleaning liquid to the milking stations, so that cleaning liquid flows through the milking stations. The method includes measuring a value of the flow of the cleaning liquid through the respective milking stations by a respective flow sensor and transferring the values of the measured flows to a control unit. The arrangement includes a first control unit and flow sensors and a respective flow sensor is adapted to measure a value of the flows of cleaning liquid through a respective milking station, and provide the values to the control unit.