Its waves covered the ruins of an extinct civilization that died out 1,000,000 BBY. Most of its land mass was located at the equator in the form of archipelagos. In addition, there were two small mountainous continents. The planet had no moons but a set of rings did orbit the planet. A standard day on Jerrilek was relatively short, and so its inhabitants had adopted a sleeping system in which they only slept every other night.
The planet was affiliated with the Galactic Empire during the Galactic Civil War and was led by an Imperial governor. It was also the home planet of Admiral Chel Dorat and his daughter Preela Dorat who lived in the city of Graleca.
Shortly after the Battle of Yavin, it was on Jerrilek that some Rebels, having escaped the Devastator, rescued the defecting Dorat from his daughter.