The present invention relates to a method for reprocessing aircraft de-icing agents comprising glycol, in which (1) the used aircraft de-icing agent, which is possibly contaminated with runway de-icing agents, is collected in a suitable device, (2) the used aircraft de-icing agent collected in this manner is subsequently brought to a glycol content of between 50 and 75% by weight without or after only course prior separation of solid or suspended impurities by expelling water (3) and the concentrate obtained in this manner is separated into a water/glycol mixture and residue by means of a thin-film evaporator, and (4) the water/glycol mixture is collected.