The invention relates to a method for controlling an asynchronous machine, which is operated below a cut-off frequency in the basic rotation speed range with a variable magnetization current and above the cut-off frequency in the field weakening range. The maximum possible fundamental frequency of the stator current (U1) is determined from the available intermediate circuit voltage or battery voltage (UB). A stator current (I1) is predefined as a set value and impressed upon the asynchronous machine. Said rotor frequency (f2alg) is calculated so as to impress the set current value upon setting the stator voltage (U1). The rotor frequency (f2) pertaining to the set current value (I1) is compared with the calculated rotor frequency (f2alg) by means of a characteristic control curve. The higher rotor frequency value thereof is used to determine the set current value. The inventive method is carried out using a microprocessor enabling the calculation algorithm to be processed quickly, effectively and close to real-time. This enables energy available in electric vehicles to used in an optimum manner.