According to the local legend, once Vilwamangalam Swamiyar, the well known Kerala Hindu saint, while travelling through Cherthala, found an idol of the Devi with its head immersed in a muddy pond. The swami understood the divinity of the idol, took it out of the mud, cleaned it and consecrated it in a temple near the pond. Thus the place is believed to have gotten its name as cher meaning "mud" and thala meaning "head" in Malayalam. The deity of the temple has the name Cherthala Karthiyayani.The word put together means "head from the mud". Unlike in other Kerala temples, the idol of Cherthala Karthiyayani Devi is consecrated in the Sreekovil just below the ground level and cannot be directly viewed by the devotees.

There is another story that says that the former name was Karappuram and that this piece of land was given by the erstwhile State of Cochin to the erstwhile state of Travancore for protecting it from enemies. The place got its name as chertha ("joined") thala ("abutting land").

Cherthala taluk is a part of Alappuzha Revenue District and Alappuzha Parliamentary constituency. All the villages of Cherthala Taluk come under the Cherthala and Aroor and Alappuzha (Constituencies of Kerala Legislative Assembly. The three-tier local governance structure is as follows: Cherthala Taluk area comes under Alappuzha district panchayat and the area is divided into three block panchayats: Pattanakad, Thycattuserry and Kanzhikuzhy. These block panchayats are again subdivided into Grama panchayats. The Grama panchayats in Pattanakkad Block Panchayath are Aroor, Ezhupunna, Kuthiathode, Kodamthuruthu, Thuravoor, Pattanakkad and Vayalar. The Thycattussery Block Panchayath have five Grama Panchayaths, viz., Arookutty, Perumbalam, Panavally, Thycattusserry and Chennam Pallippuram. Kadakkarappally, Cherthala South, Kanjikuzhi, Thanneermukkom and Mararikulam North are Grama panchayaths in the Kanjikuzhi block.