A Republic sort-of-but-not-really-noir, an unknown film, no reviews on IMDb, 23 votes. The IMDb plot summary has SPOILERS.
"Dr. Ralph Snyder and Dr. Frank Blake open an office together but soon split over a rivalry for nightclub singer Diana Wayne and a difference over ethics. In an effort to make some quick money and marry Diana, Blake becomes a retainer for gangster Joe Grant while the upright (and uptight) Sawyer becomes a medical examiner in the district attorney's office. Grant is involved in a murder and forces Blake to remove an identifying scar, thereby proving that all gangsters should keep a doctor on retainment. But Blake has a change of heart and shows up at Grant's trial, spills the beans and Grant is convicted. Consequently, Blake loses his license, Diana and then his life, proving that the 'do-tell' doctor should have heeded the film title."
Douglas Fowler plays the gangster (he has a protection racket) who seduces Blake (Edward Norris) whose Park Avenue ambitions lead him astray, but not easily. Ralph (John Beal) remains upright, and he's no snitch either. All these capable b-players went on to lots of other good work.
Now-quaint depiction of doctors scrambling for business and making house calls! This was true in the 40s. Florence Rice is the romantic interest. Ward Bond is Fowley's thug. Grady Sutton provides comic relief.