The patron saints of Lastovo and the people of Lastovo are the holy brothers Cosmas and Damian (Kuzma and Damjan) who were early Christian saints-martyrs and who as teachers in the Catholic church were physicians and healers. The parish church in which is located the work of Giovanni Lanfranco, one of the best Roman craftsmen of the 17th century, is dedicated to them.

Each year on September 26 the people of Lastovo celebrate their heavenly patron saints St. Cosmas and St. Damian.  At that time the holy mass gathers not only believers from the island but also from all over Dalmatia. A significant number of them come especially for this occasion from overseas countries where they have live since they emigrated back in the 1950s. This is an opportunity to participate with the local people in the mass celebration and procession and folk festivals which are organised and which haven't lost anything of their genuine simplicity and authenticity during the years.

Especially important was the ceremony in September 2010, because a very rare anniversary was celebrated: 700 years of the Lastovo statute. Not many even larger centres can be proud of such historical continuity.