Erattupetta is located in the eastern part of Kottayam district, acting as a geographic transition zone between the rolling midlands of Kerala and the steep, forested hills of the Western Ghats. The town's defining geographic feature is the Meenachil River, which is formed by several streams originating in the Western Ghats that converge in and around the town.
The town is surrounded by a lush, green landscape characterized by dense tropical vegetation, rubber plantations, and spice gardens. Because of its location at the foothills of the high ranges, the terrain immediately east of Erattupetta climbs sharply toward the hill stations of Vagamon and Peerumedu, while the western side slopes gently toward the plains of Palai and Kottayam.