[3] Efforts to precisely date the Rüstem Pasha Mosque have proved difficult, in part because of the lack of a foundation inscription.

The mosque has a double porch with five domed bays, from which projects a deep and low roof supported by a row of columns.

[3] The Rüstem Pasha Mosque marked a substantial deviation from his typical style (and traditional Ottoman architecture) as it relied heavily on İznik tiling instead of favouring a more sparse interior.

The Anatolian town of İznik was the heart of the Ottoman ceramics industry, which became a central component of the empire's artistic production after the conquest of Constantinople in 1453.

[3] The Rüstem Pasha Mosque is famous for its large quantities of İznik tiles in a very wide variety of floral and geometric designs, which cover not only the façade of the porch but also the mihrab, minbar and walls.

[17][18] Some of the tiles, particularly those in a large panel under the portico to the left main entrance, are decorated with sage green and dark manganese purple that are characteristic of the earlier 'Damascus ware' colour scheme.

[20] According to Willis, some of the tiles in the Rüstem Pasha Mosque are of European origin (specifically Italian and Dutch) and also date to the eighteenth century.

[6] The Rüstem Pasha Mosque's qibla wall includes a number of new and experimental painting styles in addition to the traditional ceramic tiles.

This is consistent with the mosque's unique emphasis on İznik tiles and parallels other buildings designed by Sinan, such as the Süleymaniye Complex.

Walter B. Denny hypothesizes that this could have been “deemed a project too large for one designer,” and that several other aspiring architects added to Sinan's contributions.

[17] Emblematic is the Rüstem Pasha Border, which consists of cobalt tiles, a white rosace, and turquoise embellishments, and recurs throughout the mosque.

The tiles in this section feature rose buds, lotus palmettes, and leaves, consistent with the floral decoration characteristic of this mosque.