The story is about the slow death of an unnamed writer on a safari in Africa. His leg is rotting away due to gangrene caused by a scratch he got on a thorn in the bush. The trivial nature of the wound that proved fatal suggests one theme, that death is omnipresent and never far away. Another main theme of the story is the opposite, focusing on the random events and feelings that make up life and how the specificity of these moments, trivial as they are, make them precious.

This takes several forms in the story. His relationship with his wife, for instance, is by turns affectionate and petulant; the writer quarrels with his wife out of pity for himself and his condition, and later, when they make up, their amiability is similarly shallow. The narrator describes their love affair as a kind of transaction: it was

all part of a regular progression in which she had built herself a new life and he had traded away what remained of his old life.

Now, in the bush, as he is dying in the care of this woman, he appreciates the improbability of this fate.

The italicized flashbacks that the writer experiences, in which he intensely remembers former moments from his life, are another example. These can be understood almost as a cliche—his life is flashing before his eyes! However, his memory of the fight he got into in Constantinople with a soldier over a girl stands out because of its detail. Similarly, his memory of how he had been thinking of an old lover, "the one who left him," and his sense that, while it was his "duty" to write of such things, now he never would, suggests that what is most precious to the writer is this lived experience, even if the "story of his life" makes no logical sense.

In “The Snows of Kilimanjaro,” as elsewhere in Hemingway's work, the ever-presence of death and how we deal with it is a significant theme. The central character of Harry doesn't deal with the ever-presence of death particularly well—but that's because he hasn't dealt with life particularly well, either.

Instead of enjoying it to the full, he's largely wasted it, along with his writing talent. The suggestion here is that if we don't make the most of our lives, then we won't be able to handle death when it inevitably arrives.

Death has been hanging around Harry virtually his whole life in the shape of the tragic deaths of people that he's known. This has made it hard for him to deal with the prospect of his own death, which could arrive at any moment, as well as having a negative impact on his ability to make the most of his life.

On this reading, leading a good life—a rich, fulfilling life full of positive experiences—can be seen as a prelude to having a good death or dying at peace with the world. But because Harry has wasted his life as well as his writing talent, such an ending will escape him.

The main theme of this story is facing death, but as with much of Hemingway, the story also explores isolation and alienation. Harry is attended by his wife Helen as he dies of gangrene poisoning in Africa, but he does not love her. He thinks, as his mind wanders over his life, of the prostitutes he visited in Constantinople in earlier years to try to alleviate his loneliness. At the end of his life, he hallucinates that Compton has come in a two-seater airplane and that they will go off to seek medical care, leaving Helen behind. In other words, Harry does not really want his wife to join him on his final journey. That Compton and the plane are symbols of death is underscored when the plane, in his reveries, flies towards Kilimanjaro—representing nature—rather than civilization: Harry is not going toward this world to get medical help, but to another world. Of course, there is no plane and no Compton, so Harry is essentially dying alone. Harry also has a sense of failures as a writer as he dies with unwritten stories inside him, feeling his life, as he puts it, has been all about (failed) poetry and rot, what he calls "rotten poetry." The story is bleak, but Harry does face death stoically.

One way to state the theme of a piece of literature is first to discover the topic of the piece, which in this case is death, and then put that into the form of a question: What does Harry's fate as a failed writer, his gangrenous leg, his dream of ascending to the white snow on the mountain, and the laugh of the hyena ("almost human") suggest about "death"? Perhaps it is something such as this:  In "The Snows of Kilimanjaro," Hemingway suggests that because we are all deeply flawed by our nature of being human, the shadow of death sharpens our desire to aspire to greatness." In any way you formulate your ideas on the theme, be sure you state it as a sentence with a subject, verb, and object, narrowing a "topic" to a universal truth about human experience.

Death is the main theme of this story. It is a story of imminent death, and as such, images, ideas and character attitudes pervade the entire story. There is an excellent and thorough explanation of this theme along with the more minor theme of artistic creation at the link below.