During basic training in the army, it was common practice for the recruits to exercise and march to the cadence of popular songs of the time to keep the trainees in sync. It also took the trainees' minds off the exercise—sometimes strenuous—that they were engaged in, and a five-mile forced march before breakfast was tolerated with little grumbling. Although the cadence was always the same, the words were often changed to reflect the reality of military duty. At the time, the words of the Coasters's hit song "Poison Ivy" were adapted to fit the life of a grunt in Vietnam. For example, "Poison ivy, poison ivy / Late at night while you're sleepin' / Poison ivy comes a-creepin' around" was changed to "Charlie Cong, Charlie Cong / Late at night while you're sleepin' / Charlie Cong comes a-creepin' around".

On arriving in Vietnam, his first assignment was with the Fourth Infantry Division, which was commonly referred to as the Ivy Division, but was given several unofficial nicknames, including the Funky Fourth and the Poison Ivy Division. Although he was only assigned to the Fourth Infantry for one-third of his tour, it was the most dangerous and memorable four months he spent in Vietnam. It seemed fitting that Poison Ivy was the perfect choice for the title of this audiobook.