First, one should note that Hemingway was a realistic novelist who did not radically innovate in terms of the genre as a whole. The Sun Also Rises, for example, uses a straightforward first person narrator and eschews the radical experimentation of James Joyce or Samuel Beckett or even Ford Maddox Ford, among the more innovative modernists.

Perhaps the most distinctive feature of his work is stylistic. Hemingway favors short sentences and simple, frequently monosyllabic vocabulary, often with a distinctive use of echoing and repetition, in many ways following the example of Gertrude Stein, but being somewhat less radically experimental. Many critics have suggested that this very simple style, avoidance of figurative language, and penchant for short declarative sentences was influenced by Hemingway's early career as a journalist.

Another distinctive feature of the Hemingway's work is the focus on a certain type of hypermasculine protagonist, often one who displays this model of masculinity in hunting or fishing, but who has difficulty in social relationships and is distinctively part of a "lost generation" that experiences social alienation. Many of his characters are rebels, but without specific causes or goals.

The beauty of nature and the inevitability of mortality are also major themes in his work and often combine in scenes or stories where a male protagonist risks death in a natural environment. Much of this is portrayed as a quest for authenticity, something that Hemingway saw in opposition to urban life. Women are often portrayed as obstacles in this quest for masculine authenticity, and many critics have criticized his novels for expressing fundamentally misogynistic views.