Is a Book Title Underlined or Italicized When Typing in APA Format?

American Psychological Association, or APA, style is a set of guidelines often used when writing in the social sciences, such as psychology, anthropology and history. APA guidelines stipulate rules for punctuation, tables, headings, statistics and citations. Citing your sources according to APA style helps you avoid plagiarism and boost your paper's credibility. When you cite or mention a book in a paper, you should italicize the title.

Formatting Book Citations

Citations of books in your Reference List should begin with the last name of the book's author, then the author's initials. Next, write the year of publication within parentheses.

After the year, list the title of the book in sentence case -- only capitalize the first word of the title and subtitle, if applicable, just as if you were writing a sentence.

Italicize the title of the book; don't underline it or any other part of the citation. Finally, list the location, followed by a colon, and then the publisher.

In-Text vs. Citation

You should also italicize the title of a book when you refer to it within the text of your paper. Unlike in your Reference List, however, the title of a book within the text should be in title case. That means you should capitalize the first word of the title and subtitle; all nouns, pronouns, adjectives, verbs and adverbs; and all words that are four letters or longer.

For example, within the text of your paper, you would write "Diagnostic and Statistical Manual of Mental Disorders," but in your Reference List, you would write "Diagnostic and statistical manual of mental disorders."