 The Tet Offensive ( Vietnamese : <unk> <unk> Tết Mậu <unk> 1968 , or <unk> <unk> <unk> <unk> <unk> <unk> Tết Mậu <unk> ) was one of the largest military campaigns of the Vietnam War , launched on January 30 , 1968 , by forces of the Viet Cong and North Vietnamese People 's Army of Vietnam against the forces of the South Vietnamese Army of the Republic of Vietnam , the United States , and their allies . It was a campaign of surprise attacks against military and civilian commands and control centers throughout South Vietnam . The name of the offensive comes from the Tết holiday , the Vietnamese New Year , when the first major attacks took place . 
