Adichanalloor Perumalkunnu Mahavishnu temple is located on Ithikkara - Ayoor Road, Adichanalloor in Kollam district, Kerala. The shrine is dedicated to Bhagwan Vishnu. The annual festival in the Perumal Kunnu Vishnu temple is held in Malayalam Meena Masam. The most important day is the Thiruvonam nakshatra in Meenam month.
The temple has a round sanctum sanctorum – vatta sreekovil. The temple has a chathur bahu murti (four hands) of Bhagavan Vishnu in standing posture. The shrine has namaskara mandapam and shrines of upa devatas.
The annual festival is noted for Vaishnava rituals and pujas including abhishekam, pushpanjali, niramala, vakacharthu etc.
The shrine observes Vishnu, Thiruvonam and Mandala Kalam.