PAF Base Masroor (ICAO: OPMR) is the largest airbase operated by the Pakistan Air Force. It is located in the Mauripur area of Karachi, in the Sindh province. The base was originally known as RPAF Station Mauripur and after 1956, as PAF Station Mauripur.
The airbase at Mauripur was established by Britain (Royal Indian Air Force, RIAF) during World War II in 1940-1941. On establishment of the Royal Pakistan Air Force (RPAF) the base became RPAF Station Mauripur. It was also often referred to by the name Drigh Road.
PAF Base Mauripur was renamed PAF Base Masroor in honour of former Base Commander, Air Commodore Masroor Hussain, who died in June 1967  due to a bird strike on his aircraft. He managed to direct the burning aircraft away from a populated area before crashing.
Masroor base has the distinction of not only being the largest base, area wise, in Pakistan but also in Asia. Before Karachi Airport, this airport had been used for domestic flights and also by the Quaid-e-Azam Muhammad Ali Jinnah, the Founder of Pakistan. It is of immense strategic importance considering it has been entrusted upon the task of defending the coastal and Southern region of Pakistan. It houses the 32 Tactical Attack (TA) Wing which comprises four separate squadrons. Masroor base also houses the Central Medical Board of PAF. All commissioned officers candidates are medically examined there and declared either fit or unfit for duty in there respective branches. All GD pilots are also regularly examined here as well for their flying fitness.