| First Round | ||||
| Eastern Bracket | ||||
| 1/16/38 | Kearny Irish | 3 : 5 | Bethlehem Hungarian | |
| 1/16/38 | New York Americans | 4 : 2 | Brooklyn First Germans | |
| 1/16/38 | Brooklyn Hispano | 1 : 1 (aet) | St. Mary’s Celtic (Brooklyn) | |
| 1/22/38 | R | St. Mary’s Celtic | 4 : 1 | Brooklyn Hispano |
| 1/16/38 | Paterson Caledonians | 1: 0 | Kearny Scots | |
| 1/16/38 | Baltimore SC | 2 : 1 | Budd AA (Phi.) | |
| 1/16/38 | German American SC (Phi.) | 3 : 3 | Passon SC (Phi.) | |
| 1/23/38 | R | German American SC | 2 : 0 | Passon SC |
| 1/23/38 | Brookhattan (NYC) | 4 : 1 | Hatikvoh (NYC) | |
| 1/30/38 | Lusitania Recriation | 3 : 3 | Ponta Delgada | |
| Western Bracket | ||||
| 1/16/38 | Maccabee SC (Chi.) | 2 : 0 (aet) | American Nickeloid (Peru, IL) | |
| 1/16/38 | Schlitz (Mil.) | 6 : 4 | Racine Deutscher (WI) | |
| 1/16/38 | Castle Shannon (W. Pa.) | 2 : 0 | Heidelberg (W. Pa.) | |
| 1/16/38 | South Side Radio (St. L) | 3 : 2 | St. Patricks (St. L) | |
| 1/16/38 | Sparta Garden City (Chi.) | w/o | Shamrocks SC (St. L) | |
| 1/23/38 | Bartunek Slavia (Cle.) | 3 : 1 | Cecil Merchants (W. Pa.) | |
| 1/30/38 | Burke Undertakers (St. L) | 5 : 4 | St. Matthews (St. L) | |
| 2/13/38 | Thistles SC (Det.) | 5 : 1 | Eckert & Becker (Det.) | |
| Second Round | ||||
| Eastern Bracket | ||||
| 1/30/38 | New York Americans | 4 : 1 | Bethlehem Hungarian | |
| 1/30/38 | St. Mary’s Celtic | 7 : 1 | Baltimore SC | |
| 1/30/38 | German American SC | 5 : 3 | Paterson Caledonian | |
| 2/20/38 | Brookhattan | 7 : 0 | Ponta Delgada | |
| Western Bracket | ||||
| 1/30/38 | Maccabee SC | 2 : 1 | Schlitz | |
| 1/30/39 | Castle Shannon | 3 : 0 | Bartunek Slavia | |
| 2/6/38 | South Side Radio | 1 : 0 | Burke Undertakers | |
| 2/20/38 | Sparta Garden City | 5 : 0 | Thistles SC | |
| Quarterfinals | ||||
| 2/20/38 | Castle Shannon | 4 : 2 | South Side Radio | |
| 2/27/38 | New York Americans | 4 : 3 | Brookhattan | |
| 2/27/38 | St. Mary’s Celtic | 1 : 1 (aet) | German American SC | |
| 3/5/38 | R | St. Mary’s Celtic | 1 : 0 | German American SC |
| 2/27/38 | Sparta Garden City | 1 : 0 | Maccabee SC | |
| Semifinals | ||||
| 3/27/38 | 1L | New York Americans | 2 : 1 | St. Mary’s Celtic |
| 4/2/38 | 2L | St. Mary’s Celtic | 3 : 0 | New York Americans |
| St. Mary’s Celtic advance on 4-2 aggregate | ||||
| 3/13/38 | 1L | Castle Shannon | 1 : 2 | Sparta Garden City |
| 3/20/38 | 2L | Sparta Garden City | 3 : 1 | Castle Shannon |
| Sparta Garden City advance on 5-2 aggregate | ||||
| Final | ||||
| First Leg – at Sparta Stadium – Chicago, Illinois | ||||
| 4/17/38 | Sparta Garden City | 3 : 0 | St. Mary’s Celtic | |
| Second Leg – at Starlight Park – Bronx, New York | ||||
| 4/24/38 | St. Mary’s Celtic | 2 : 3 | Sparta Garden City | |
| Sparta Garden City win National Challenge Cup on 6-2 aggregate | ||||
| KEY – w/o – Walkover, R – Replay, 1L – 1st Leg, 2L – 2nd Leg, 3L – 3rd Leg | ||||