Robe Offering Ceremony (Kathina Dana)

The Buddha himself made the rule of offering robe (civara) to monks after the rain treat a long time after other rules were made. In Nepal, too, the rule was enforced due to practical necessity. Various sub-rules were also made under it. Once when the monk went to pay obeisance to the Buddha after the retreat, it rained hard. They were drenched through and unable to walk further. There were no others Civaras to put on for a monk could possess only three Civaras and had already used all of them. They saluted the Buddha and sat down nearby. The Buddha asked, ―Are you all well? Was food served well? Did you stay happily?‖ They replied, ―Bhante! Everything is all right. But, it rained hard and we are wet through and suffered a lot. We are unable to move forward.

Rain Retreat (Varsa - Vasa)

The term retreat means staying at one place for three consecutive months, i.e. from July to October.
Sumangala Vihara celebrates the Rain Retreat. In this occasion, monks come to stay here. They live here from July to October. From this Vihara, monks go to next Vihara to next vihara for Rain Retreat. The Rain Retreat usually ends with the Kathina ceremony, where the laity gives the monks robes and other needed items, and the monks read certain sutras for the benefit of the deceased.

Gulah Dhamma-Desana

Gulah is a month long practice during the period from full moon of August to full moon of September (Sravan to Bhadra). It is a festival celebrated by Newar Baudha community. In the first time, it was celebrated in Sumangala Vihara in 2011. This vihara continued this celebration in 2012. But now, it has been celebrated on live telecast at Nepal Mandala Telvision since 2013.

Bishak Purnima

Vesak Purnima is the birthday of the Buddha and the most important festival in Buddhism. On the first full moon day in May, Buddhists all over the world celebrate the birth, enlightenment and death of the Buddha in a single day. It celebrates the Buddha's birth, his attainment of enlightenment, and his death, which Theravadin believe miraculously occurred on the same day.
Similarly, Sumangala Vihara celebrates Vesak Purnima. In this day, lay people gather at a monastery to hear the telling of the story of the Buddha's life, wash the sacred Buddha images, observe the Five Precepts, and circumambulate the reliquary. Monks, Buddhists scholars and gurus worship Buddha puja by offering, bowing, and chanting. In this day, there is special feast organized by this vihara for Buddha Sangha.

Amai Puja

Amai Puja is one of the ritual practices of in Sumangala Vihara. It is celebrated in the Vihara around for 60 years. This practice has been started by Buddhaghosh Mahathera after he returned from Burma. This practice is peformed at the day of dark moon (Aunsi) in Sumangala Vihara whereas same ritual is celebrated at the day of fool moon in Anand Kuti Vihara. The lay Buddhist invidually or Sumangala Vihara organizes meal (vojan) for monks, nuns, novices and lay Buddhist followers. Without invitation monks, nuns and novices come in this vihara to meal. Sumangala Vihara has become popular among the Buddhist followers of Kathmandu Valley at the day of dark moon because due to Amai Puja. So, Amai Puja is one of the important features of the Vihara.

One Day Meditation Camp(Eka Divasiya Dhyan Shivir)

One day Meditation Camp program began on 8th Aug. 2015. The concept of is provided by Ven. Pannasara. It is performed on third Saturday of every month in Sumangala Vihara. It is twelve hours of long program. It begins at 8 a.m and ends at 4 p.m. Around 150 persons participate in each camp. Now, the camp is conducted by Sumangala Baudha Sangha and Yehi Passika Foundation.