The International Labor Defense (I.L.D.), the legal arm of the Communist Party of the United States of America, was formed in 1925 to counter groups like the Ku Klux Klan and to defend high profile, controversial cases like that of anarchists Nicola Sacco and Bartolomeo Vanzetti, who were ultimately executed for robbery and murder.

A representative of the communists attended the first trial in Scottsboro and immediately realized the case had the potential to energize a large constituency. Earl Russell Browder, general secretary of the American Communist Party at the time, later claimed, "The communists were the first to initiate organized action on behalf of the blacks. The [Angelo] Herndon Case and the Scottsboro Case in the early thirties established that. ...We were the ones that made the Scottsboro Case. The rest of the country would never have been interested in it if we hadn't made it an international issue." Though Browder may have overstated his case, ignoring the efforts of other organizations including the NAACP, the communists clearly did play a major part in making the Scottsboro case visible to a wide audience early on in the legal proceedings.

Joseph Brodsky of the I.L.D. began by hiring a Southern lawyer named George Chamlee Sr., one of the few southerners who would defend a communist's right to free speech. Brodsky then met with the young defendants and gained their confidence, guaranteeing they would have a stronger defense than they had at the first trial.

The NAACP's interest in defending the Scottsboro Boys led to active antagonism between the two groups. The NAACP thought the I.L.D. was using the Scottsboro case as propaganda for their cause; the I.L.D. thought the NAACP was too moderate, willing to collaborate with the ruling class for small gains. The defendants were easily swayed by both organizations, but ultimately the I.L.D. was more successful at courting their parents, and that decided the issue.

To dispel accusations that they were going to martyr the Boys for propaganda purposes, the I.L.D. hired a prominent attorney, Walter Pollak, for the first appeal to the Supreme Court, and Samuel Leibowitz for the subsequent trials. Leibowitz was one of the most successful defense attorneys of the day, and he took the case with the understanding that he would not receive any fees.

In 1934 two lawyers associated with the I.L.D. were caught with a bribe intended for Victoria Price for changing her testimony. This was the most egregious of several public acts and protests that Leibowitz felt were detrimental to the work of the defense. He compared the stupidity of the attempted bribery to an assassination of the defendants. Their already strained relationship broke, and Leibowitz continued to defend the boys under the auspices of the American Scottsboro Committee (A.S.C.).

A year later, the conflict between the I.L.D. and the A.S.C. reached a sort of compromise, in part because of pressure from international communists who were courting public opinion for the growing conflicts with fascists in Europe. The I.L.D. joined the A.C.L.U., NAACP and others to form the Scottsboro Defense Committee to administer the legal defense. As just one voting member in the group, the I.L.D. ceded its prominent position in the Scottsboro case.