Bred in Yorkshire at the Sledmere stud by Lady Sykes, and purchased for HH Aga Khan III (1877-1957) by trainer Hon George Lambton (1860-1945) in 1922, she would become a brilliant racehorse. She was described as a "superb filly, combining size, quality, and faultless conformation with a fine bold outlook." Her dam, Lady Josephine (ch f 1912), also produced Lady Juror (b f 1919 Son-in-Law), the second dam of the Oaks winner Commotion (b f 1938 Mieuxce).

In her maiden appearance in the Spring Stakes at Newmarket she had left the field behind at only three furlongs, and set a course record of 57 4/5 seconds for five furlongs. In her next start, the Queen Mary Stakes, she won by ten lengths, and it is said, won the nickname "The Flying Filly" from British racing journalists. She reeled off victories in the National Breeders Produce Stakes by four lengths, the Molecomb Stakes by ten lengths and Champagne Stakes by three lengths. In her final outing in October, she was said to be a bit off-color and the ground a bit heavy for her liking; even so she dug in and managed a second place. Her efforts as juvenile saw her awarded top spot on the Free Handicap. Sent out as a three year old for the One Thousand Guineas, she failed to stay, resulting in a second place finish to Plack. She was tried once more over a mile in the Coronation Stakes although it became clear this was too long a distance. Her final outings, in the six furlong King George Stakes and the five furlong Nunthorpe Stakes, saw the return of her formerly brilliant self. Some say she was the fastest filly to set foot on the English turf.

In the stud she produced six winners: the very fast two year old Mirza, Badruddin, Furrokh Siyar, Mah Mahal, Mumtaz Begum and Rustom Mahal. Her colts were better than her fillies, who were somewhat disappointing. However, when her daughters retired to stud their influence would be profound. Mah Mahal foaled Mahmoud, Pherozshah, Khan Bahadur, Mbale and Mah Iran; Mumtaz Begum bred eight winners including Nasrullah, Dodoma, Sun Princess, Malindi, Bibibeg and Rivaz; while Rustom Mahal produced Fille du Regiment and Abernant.

Among her notable descendants are Mahmoud (gr c 1933 Blenheim), who won the Epsom Derby in record time and became a Leading Sire in 1946 in America, and 3rd on the Sires' List in 1942 in Great Britain, and Nasrullah (b c 1940 Nearco), who won the Champion Stakes and a third in the Epsom Derby and went on to become a Leading Sire in 1955, 1956, 1959, 1960, 1962 in America, as well as a Champion Sire in Great Britain.

Many classics winners descend from Mumtaz Mahal. Those from her daughter Mah Mahal include In a Tiff (Derby Italiano), Mahmoud (Derby Stakes), Migoli (Prix de l'Arc de Triomphe), Nishapour (Poule d'Essai des Poulains), Petite Etoile (One Thousand Guineas, Oaks Stakes), Prince Arthur (Premio Parioli) and Tanino Gimlet (Tokyo Yushun). Aliysa was disqualified from winning the Oaks Stakes but was later Champion Broodmare. Those from Mumtaz Begum include Ameerat (One Thousand Guineas), Ginetta (Poule d'Essai des Pouliches), Kalamoun (Poule d'Essai des Poulains), On the House (One Thousand Guineas), Octagonal (AJC Australian Derby), Oh So Sharp (One Thousand Guineas, Oaks, St. Leger), Risen Star (Preakness and Belmont Stakes), Shantou (St. Leger), Morshdi (Derby Italiano) and Shergar (Derby Stakes, Irish Derby, King George & Queen Elabeth Diamond Stakes).

Mumtaz Mahal was in the Aga Khan's stud in France when war broke out. When the stud was overrun by the Germans they left her behind, perhaps due to her age, or perhaps out of respect; she died there in 1945.