An electrical control device for a motor-driven derailleur for bicycles. The control device has a supporting body adapted for attachment to the handlebars of the bicycle. A brake lever is mounted on the supporting body so that it can oscillate. A pair of switches, for controlling gear change, are carried by the supporting body. The switches are preferably mounted on a supporting plate that is located on the supporting body. Preferably, the switches are pre-assembled on the support plate before the plate is positioned on the supporting body.