Sasthamcotta Sree Dharma Sastha temple is located at Sasthamkotta in Kollam district, Kerala. The 10-day annual festival in Sasthamcotta Sree Dharma Sastha temple ends with Arattu on Uthram nakshatra in Kumbham month.
The main rituals during the annual festival include Tri Kodiyettu, Thiruvabharana Ghosha Yatra, Pallivetta and Arattu.
Sastha is worshipped as Prabhasatyaka samethan. The murti is swayambhu and faces east. The Upa Devatas worshipped in the temple are Ganapathy, Shiva, Nagaraja, Nagayakshi, Yogeshwaran, Rakshas and Madan.
The shrine is situated on the banks of Sasthamcotta Kayal.
This is one among the 108 Ayyappa temples mentioned in the Thottam Pattu. In Thottam Pattu the temple is known as Markkadakavu.
The place belonged to Kayamkulam kings during the ancient times. But the Prathishta in the temple was done by Pandalam King.
Monkeys in the vicinity are considered divine and devotees offer food to them. Similarly, the fishes in the Sasthamcotta Kayal are also considered divine and they are fed by people visiting the temple.