Disclosed is a method for deacidifying a fluid stream containing acidic gases as contaminants, according to which the fluid stream is brought into intimate contact with a washing liquid in at least one absorption step. Said washing liquid represents an aqueous solution containing a) tertiary aliphatic alkanolamines (alkanolamine A), at least 30 percent by weight of said tertiary aliphatic alkanolamines being 3-dimethylamino-1-propanol, and b) secondary aliphatic amines (activator B), at least 20 percent by weight of said secondary aliphatic amines being piperazin. The fluid stream which has been essentially purified of the acidic gases is then separated from the washing liquid that is loaded with acidic gases.