http://en.wikipedia.org/wiki/Vietnam_War_casualties

The Army of the Republic of Vietnam ARVN lost about 266,000 killed from 1959 through 1975. R.J. Rummel's range was 216,000 at the low end and 316,000 at the high end.[1] Lewy, from US Department of Defense's document, report ARVN suffered 220,357 killed from 1965 through 1974. A PBS estimate was a quarter of a million men killed in action.
Rummel's review of the various data led to a mid-level estimate of 843,000 civilian deaths in both North and South Vietnam. The detailed Figures are not complete, but the mid-level R.J. Rummel estimates are that around 391,000 South Vietnamese civilians died. Another 643,000 died as the communist North Vietnamese consolidated power after their victory in 1975. Rummel's low-level estimate was 361,000 South Vietnamese civilians and his high-estimate was 720,000.
According to the government in Hanoi, 1,100,000 North Vietnamese Army and Viet Cong military personnel died during the Vietnam War[4] Rummel reviewed the many casualty data sets, and this number is in keeping with his mid-level estimate of 1,011,000 North Vietnamese combatant deaths.[1] He further calculated a mid-level estimate of 251,000 Viet Cong military deaths.