Constructed entirely in cut and dressed bricks laid in kankar lime with a scanty sprinkling of red sandstone in the gate and the transept, the gorgeous Wazir Khan Mosque, stands tall near the Delhi gate of the walled city of Lahore. With its tall, impressive octagonal minarets, decoration of glazed tiles adorned with faience work and the interior almost entirely embellished with elaborate frescoes, the Wazir Khan Mosque is reckoned as the most ornately decorated mosque of the Mughal era. Commissioned in 1634 by the chief physician to the Mughal Court, Hakeem Ilam-ud-din Ansari, widely known as Wazir Khan, the mosque was constructed during the reign of the Mughal Emperor Shah Jahan, as a part of an ensemble of buildings, which also included the nearby Shahi Hammam Baths.

Covering a massive area of 279 feet (85 m) by 159 feet (48 m) and its four 170 feet (51.8 m) tall gracefully dignified minarets defining the corners of the main courtyard, it took around seven years to complete the mosque in 1641.

The Wazir Khan Mosque was built to enclose the tomb of an esteemed Sufi saint Syed Muhammed Ishaq, also known as Miran Badshah, who had migrated from Iran in the 14th century. It was built on an elevated plinth, with the main entrance onto the Wazir Khan Chowk, a town square located in the walled city of Lahore. The façade of the main entrance is decorated with elaborate tile work and calligraphy, which includes verses of the Quran and calligraphic insignias. Façades facing the inner courtyard are also richly embellished with motifs and palettes, which display strong influences from 17th century Persia.

The Persian-influenced motifs, which include star-shaped flowers and grapevines, were created by using Persian-style colours, like green, cobalt blue (lajvard), sky-blue (firozi), orange, yellow, purple and white, which magnified their beauty.

Entry into the mosque is through a large iwan, a rectangular and vaulted hall or space, which is walled on three sides with one end entirely open, flanked by two projecting balconies. The upper part of the iwan is adorned with the Islamic declaration of faith written in intricate tilework. Entry through the small portal leads into a covered octagonal chamber, located in the centre of the Calligrapher's Bazaar of the mosque. Passage through the portal and the octagonal chamber leads into the enormous central courtyard, measuring 160 feet by 130 feet (48.76 x 39.62 m), featuring high arched galleries surrounding a central brick-paved courtyard, which is a typical feature of imperial Persian mosques in Iran. Apart from a pool, measuring 35 by 35 feet (10.66 x 10.66 m), used for the Islamic ritual washing before prayer, the courtyard also features a subterranean crypt, containing the tomb of Syed Muhammad Ishaq Gazruni, a 14th century Sufi Saint, also known as Miran Badshah. The huge courtyard is flanked on the northern and southern sides by 32 hujras or cubicles, for prayer or study for religious scholars and two pavilions facing each other across its width.

The prayer hall of the Wazir Khan Mosque, located at the westernmost portion of the mosque and measuring around 130 feet (39.62 m) long and 42 feet (12.80 m) wide, is divided into five segments, which are aligned into a single long aisle running north to south.

The walls of the prayer hall are also decorated with calligraphy, both in Arabic and Persian. The central section of the prayer hall is topped by a massive 31 foot tall dome with a diameter of 23 feet, resting upon four arches that form a square pavilion which is a Persian form of architecture, known as Char Taq. The inner side of the dome is meticulously painted with intricately designed frescos, displaying different types of fruit on silver platters, pitchers of wine and trees in pairs, which unmistakably symbolises the Jannah or the paradise, according to the Quran. The unique acoustic properties of the dome allow for the sermon of the Imam to be projected across the courtyard of the mosque. Apart from the central section, the remaining compartment in the prayer hall is topped by a 21 feet (6.40 m) tall dome with a diameter of 19 feet (5.79 m), built in a style similar to that of the earlier Lodi dynasty that ruled the Delhi Sultanate from 1451 to 1526.

The Wazir Khan Mosque lost its imperial status in 1671, when the larger Badshahi Mosque was built closer to the royal palace and the majestically adorned mosque, which once was an exclusive space for the king, was opened to the community and continues today as a place of public worship. But negligence and lack of proper maintenance for centuries gradually created havoc on the structure. Inadequate infrastructure for sewage and rain drainage slowly exposed the walls of the mosque to water damage, causing frescos to crumble. Exposure to harsh weather degraded the glazed tile work and caused the fading of the vibrant colour of the brickwork. Apart from natural wear and tear, the mosque had to suffer bitterly due to natural calamities like earthquakes and its minarets leaned outward and some of the domes and walls cracked. In addition, encroachment of illegal shops blocked off much of the mosque from the surrounding neighbourhood and tangled power lines further spoiled views of the mosque.

Although the site was added to the tentative list for UNESCO World Heritage Site in 1993, the Government of Punjab in Pakistan embarked on conservations and restoration efforts for the mosque only in 2004. Finally, a project named the Pilot Urban Conservation and Infrastructure Improvement Project - the Shahi Guzargah Project, was launched by the Government of Punjab and the Aga Khan Trust for culture in 2012. In the first phase of the project, the illegally constructed shops were removed, restoring views of the mosque. However, the entire project was completed in 2015, with the help of the governments of Norway and the United States, which restored a section of Shahi Guzargah between the mosque and Delhi Gate.