The church has stained glass on various windows and openings. The ones done by the stained glass maker Joan Vila-Grau since 1999 are outstanding; they are made of panes of different colours fixed with lead and concrete. In these pieces of stained glass, Vila-Grau symbolises specific themes through the masses of colour.
The first stained glass windows to be placed were in the transepts, and they express the symbology conceived by Gaudí. The main window of the transept of the Passion façade represents the resurrection, the stained glass of the sides and the main nave will symbolise the saints and shrines linked to the local church represented on each column. The upper stained glass windows of the side naves will illustrate Jesus" words "I am the way, the truth and the life", "The resurrection", etc. The stained glass windows in the central nave will have no colour and will be made with plain, translucent or opaque glass to symbolise purity, and to allow the maximum amount of light to enter the interior.
Vila-Grau"s designs have been made by Josep Maria Bonet"s artistic stained glass company, which had already produced other stained glass windows for the church, such as the ones in the crypt.