The splendid physique of Tony Curtis is given generous screen exposure in the boxing melodrama The Square Jungle. Curtis plays Eddie Quaid, who turns to pugilism to bail his wino father (Jim Backus) out of jail. Gaining fame as "Packy Glennon," Quaid inevitably forgets the things in life that are truly important, including his faithful girlfriend Julie Walsh (Pat Crowley). Only after he nearly kills a longtime rival in the ring does Quaid get his act together. The most compelling performance is delivered by Ernest Borgnine as Quaid's trainer; Borgnine plays the character as a shy, studious type, adding a highly original touch to this otherwise predictable production.
~ Hal Erickson, All Movie Guide