[1] Mosconi pioneered and regularly employed numerous trick shots, set many records, and helped to popularize pool as a national recreation activity.

Mosconi set the officially-recognized straight pool high run world record of 526 consecutive balls in 1954.

Despite that, Joseph was strongly opposed to his son playing pocket billiards, preferring he become a Vaudeville performer like his cousins, the dancers Charles and Louis Mosconi.

He tried to keep his young son away from the game by hiding the billiard balls, but Willie improvised by practicing with an old broomstick and small potatoes from his mother's kitchen.

The young Mosconi was a prodigy and his father soon realized that he could use his son's talent to help earn money for their growing family.

Joseph Mosconi began advertising challenge matches, and though Willie had to stand on a box in order to reach the table, he beat experienced players many years his senior.

The hall was packed, and though Greenleaf won that match, Mosconi played well enough to draw considerable attention and launch his professional career.

Mosconi retired from tournament play in 1966, after once again making it to the final of the World Straight Pool Championship but losing to Joe Balsis.

Mosconi set the world record by running 526 consecutive balls without a miss during a straight pool exhibition in Springfield, Ohio on March 19–20, 1954.

[11] Critics have argued that Mosconi's record was made in competition while Schmidt simply set up break shots for himself, and that his video was never released.

[12][13] In similar fashion to Schmidt, on January 18, 2022 as part of the "Legends of Pocket Billiards" high run series, Jayson Shaw completed a 51-rack record-breaking run of 714, however, after review of the unedited video by a BCA committee of 5 people it was noted that on the 45th ball, Jayson Shaw inadvertently touched an object ball.

[14] Mosconi's record was set on a 4 × 8 foot Brunswick table with 5 1/4 inch corner pockets at the East High Billiard Club.

Mosconi was the technical advisor on the 1961 film The Hustler, starring Paul Newman, Jackie Gleason, George C. Scott, and Piper Laurie.

[4] Mosconi also had a cameo role as himself, acting as a stakes holder during the first match-up between the film's characters "Fast Eddie" Felson and "Minnesota Fats".

1950–57: Mosconi appeared on Toast of the Town later known as The Ed Sullivan Show on April 23, 1950 and January 6, 1952, September 25, 1961: Theatrical release of The Hustler (see above).

February 25, 1978: "The Great Pool Shoot-Out", a US$15,000 match between Rudolf "Minnesota Fats" Wanderone, Jr. and Mosconi at the Waldorf-Astoria Hotel in New York City.

Throughout the 1970s and 1980s: Mosconi made several other television appearances competing in challenge matches with other legends such as Jimmy Caras, Luther Lassiter, Irving Crane, Joe Balsis and "Fats" Wanderone.

1982: He appeared in the music video for George Thorogood's "Bad to the Bone", as a spectator and betting on Bo Diddley's character.

August 10, 1991: Mosconi played his last challenge match, against Jimmy Caras at the Valley Billiards Hall of Fame tribute dinner show.