Tharaka-Nithi County is home to the Chuka, Muthambi, Mwimbi and Tharaka subgroups of the Ameru community.

The county consists of three constituencies: Maara, Chuka/Igambang'ombe, and Tharaka.

Subsequently, Meru South, also known as Nithi, combined with Tharaka into the Tharaka-Nithi District.

In 1998, the Tharaka-Nithi District was split into two districts, Nithi and Tharaka,[3] but a 2009 High Court decision declared that split unconstitutional and re-combined the two.

Crops planted include tea and coffee in the higher areas of the county while sorghum, maize, green grams and millet in the low altitude areas.