The Cahuenga Branch Library is significant for its cultural role as part of the history of the East Hollywood community. It is a notable architectural design, and was the last and the smallest of the six branch libraries of the Los Angeles Public Library big huge system built with a $200,000 grant from Andrew Carnegie. The Cahuenga Branch along with the Vermont Square and the Lincoln Heights Branch Libraries are all that remain of the original six City Carnegie Branch Libraries. It is part of a thematic grouping of City libraries which has been nominated to the National Register of Historic Places.

At the turn of the century, the East Hollywood community numbered about 500 people who worked orange and avocado groves and wheat fields. Initial efforts to build a library began when citizens offered to purchase land near the intersection of Vermont Avenue and Santa Monica Boulevard. However, the present site was acquired later by assessment proceedings and the Cahuenga Branch Library was established. The branch's name derives from its location in the Cahuenga Valley, an old name for the area south of the Hollywood Hills.

In his dedicatory address, City librarian Everett R. Perry proudly pointed to the new branch's modern features: bookshelves accessible to all, several thousands of carefully selected children's literature, and a public auditorium intended by the Library Board to be widely and liberally used. From its opening, the library has served the diverse community of East Hollywood. Initially, it serviced modest middle-class residents, the affluent Los Feliz area, and students attending the many nearby colleges. As the population of East Hollywood shifted to one of the most ethnically diverse areas of Los Angeles, the Cahuenga Branch Library has responded with a diversity of services. The library offers outreach programs in citizenship and films for convalescent homes. It maintains a staff which is multilingual.

From its inception, the branch was intended to serve as a community center as well as a library. An auditorium with overflow capabilities and a stage were designed to be easily accessible a few steps below street level. During World War I, a busy Red Cross Auxiliary, food conservation classes, Liberty Loans, and thrift stamp sales were held here. In the 1920s, with the rising popularity of the movie industry, theatre rehearsals, music recitals, and community sings were held in the auditorium.

The library building is an outstanding example of public architecture. The architect for the library, Clarence H. Russell, was a noted local architect who had designed numerous churches, schools, and houses in the Venice community. Its formal Italian Renaissance styling with Palladian motifs, cast-stone balustrades, decorative brick treatment, and prominent hipped roof are uncommon in branch library design.

Its formal design and public accessibility accentuate its relationship to the street. The Cahuenga Branch Library stands out in an area which has few other buildings that are noteworthy.