This is the most prestigious medieval church in Mqabba. It was the first church used even when the village was declared as a separate parish in 1598 by Bishop Gargallo. An engraved date indicates that it may have been built in 1515 although there is the possibility that this was the date of one of the enlargements of the chapel and the most probable date for the original building is 1486. The dedication of this chapel to St. Basil indicates the strong roots of the Basilian community in Malta. The 1600 Gargallo Visitation Report describes a very well equipped church of St. Basil, 'nupereractam' to the status of parish church.
The report contains valuable information. The church had three altars. The main one in the chance was surmounted by a painting on wood showing the Virgin accompanied on one side by St. Basil and on the other by Joseph Confessor. A side altar of the Rosary had a painting of the Virgin of the Rosary surrounded by insets of the fifteen Rosary Mysteries. This altar stood on the left hand side of the chancel and opposite it on the right hand side was a third altar dedicated to the Visitation surmounted by a painting depicting the Virgin visiting Elizabeth. St Basil is adjacent to another very old church, that of St. Michael, which was built in 1550 and again in 1669. The parvis of the St. Basil Chapel was used as a cemetery for the victims of the 1675 Plague. A monument was erected in the same parvis to commemorate the deaths of Rev. Valerio Zammit, Rev. Luca Zammit and the parish priest Rev. Domenico Pace who all died of the plague.