| Issue | #40 |
| Published | May-June 1946 |
| Cover Price | 0.10 |
| Pages | 52 |
| Editing | Whitney Ellsworth; [Jack Schiff; Mort Weisinger] |
| Notes | inker credit by Bob Hughes 12/04 |
| Characters | Superman; Mr. Mxyztplk; Susie Thompkins |
| Genre | superhero |
| Pencils | Wayne Boring |
| Inks | George Roussos? |
| Notes | inker credit by Bob Hughes 12/04 |
| Characters | Superman; Mr. Mxyztplk (villain); Susie Tompkins; Lois Lane; Zrfff; Daily Planet Building |
| Synopsis | Lois thinks Superman is making Susie's fibs come true again, but Susie is actually telling the truth about things Mr. Mxyztplk is doing. Superman prevents any real damage from Mr. Mxyztplk's tricks until he can get him to say his name backwards and return to his own dimension. |
| Genre | superhero |
| Script | Don Cameron |
| Pencils | Ira Yarbrough |
| Inks | Stan Kaye |
| Notes | Inker credit by Bob Hughes 12/04, writer credit by Martin O'Hearn. |
| Reprinted | in Limited Collectors' Edition (DC, 1972 series) #C-38; in Superman in the Forties (DC, 2005 series) #nn |
| Characters | Superman; Professor Walter Whiffensniff (intro); Flatnose Flannigan (intro, villain); Perry White; Lois Lane |
| Synopsis | A noted Professor believes that Superman is scientifically impossible and therefore must be a hoax. |
| Genre | superhero |
| Script | Jerry Siegel |
| Pencils | Ira Yarbrough |
| Inks | Stan Kaye |
| Notes | writer credit by Martin O'Hearn. Based on a daily newspaper sequence by Alvin Schwartz. |
| Reprinted | in Superman (DC, 1939 series) #246 (December 1971) |
| Script | Lit-Win |
| Pencils | Lit-Win |
| Inks | Lit-Win |
| Script | Ed Blaney |
| Letters | typeset |
| Characters | Lois Lane; Superman (as Clark Kent); Steve Bard; Johnny Roberts (intro) |
| Genre | superhero |
| Script | Whitney Ellsworth |
| Pencils | Sam Citron |
| Inks | Stan Kaye? |
| Notes | writer credit by Martin O'Hearn and Richard Morrissey, inker credit by Bob Hughes 12/04 |
| Characters | Superman; Kublai Khan (intro); Mai-Lin (Khan's daughter); Bonzac (intro, villain); Garjnok (intro, villain); Perry White; Lois Lane |
| Genre | superhero |
| Script | Don Cameron |
| Pencils | Ira Yarbrough |
| Inks | Stan Kaye |
| Notes | inker credit by Bob Hughes 12/04 |