Paashaankusha Ekadasi is observed on the 11th day of the bright fortnight in Ashwayuja maasam i.e. the next day after Vijayadasami. Paasham refers to Yama Paasham - the noose used by the God of Death to take away the soul of those whose time has come. Ankusham is the weapon which stops the Paasham. Hence, this ekadasi gives one the benefit of putting a stop to untimely death.

The Ashwayuja Masa falls in Sharad Ritu which is a transition time between the monsoon and winter. We often notice that many people fall ill during such seasonal transition. Hence, by observing a fast on this day and worshipping Lord Vishnu one can overcome many serious ailments and the fear of death itself.

Traditionally, Tulasi puja begins on this Ekadasi. Tulasi is worshipped in the evening with offerings of 5 ghee lamps, 5 types of flowers and 5 types of fruits and the tulasi worship goes on for a month till Kartika Pournami when Tulasi Vivaaha with Lord Krishna is performed.

You can offer a pooja on auspicious Ekadasi  at famous Vishnu temples from Parihara.com