Abstract: A vehicle cruise control apparatus having an automatic transmission system comprises a calculator for calculating the optimum gear position of the transmission system for minimum fuel consumption for the vehicle operating condition at each instant, a circuit for temporarily releasing the cruise control operation carried out by a controling circuit when the optimum gear position is not coincident with an actual gear position, and a control circuit responsive to the result of the calculation for automatically shifting the transmission to the optimum gear position during the release condition of the cruise control, and the cruise control operation is automatically restored when the gear change operation is completed, whereby economical vehicle operation is carried out without inconveniencing the driver when the car is being driven in the cruise control mode.