The Japanese modeling magazine, Model Graphix, began to serialize an original monthly Gundam novel named Gundam Sentinel (ガンダム・センチネル). The series ran from 1987, until its conclusion in the month of August in 1988. Gundam Sentinel became a cult hit, due to its super-detailed mechanical designs of the series and the intricate story by veteran writer and Mobile Suit Gundam fan, Masaya Takahashi. Set during the same timeframe as Mobile Suit Gundam ZZ, after the fall of the Titans the Earth Federation sends an expeditionary force called Task Force Alpha, to deal with a group of elite Federation officers who have formed their own Earth-supremacist faction, the New Desides.

Gundam Sentinel took on a much more realistic, technical style of thinking and look at the Gundam universe, where mobile suits were seen more as fighter jets or military weapons, rather than as cartoonish robots. They were larger, their weapons more powerful than their predecessors', the characters were older and the plot was on a smaller scale than what is usually found in other Gundam. It also marked the debut of Hajime Katoki, who would become one of the franchise's most prolific mechanical designers. Gundam Sentinel is perhaps the best-known Gundam side-story ever written, and is said to be for the most mature of Gundam fans.

The series was never animated (although a short animated television commercial for a Gundam Sentinel model kit was made) or released as a manga. However, the model kits continue to be popular among Gundam fans and new Sentinel designs crop up every now and then.

After Gundam Sentinel completed its run, all of the individual articles were compiled by Model Graphix, some new material and artwork was added, and it was published as a 320-page photo-novel, under the title Gundam Wars III. It was released in September of 1989, is highly regarded as one of the best Gundam novels ever written.

In July of 1990, the story was again republished as a novel titled Gundam Sentinel: Alice's Confession.