A sleep prevention device while driving a vehicle including a housing member having an interior compartment; and the interior compartment includes a movable cord member with a distal end and a proximal end having a first contact member on the cord member. The interior compartment also includes two spaced-apart second contact members for engagement by the first contact member. The sleep prevention device further includes an earpiece assembly having an earpiece housing member with an alarm member therein connected to a speaker member in the earpiece housing. The distal end of the movable cord member is connected to the earpiece assembly. The first contact member moves in either a forward direction or a rearward direction as the driver's head moves as the driver starts to doze or fall asleep such that the first contact member moves and engages one of the second contact members in order to activate the alarm member and produce an alarm sound in the driver's ear from the speaker member of the alarm member for awakening the driver from his/her dozing or sleeping state.