Kilimanjaro is the highest mountain peak in Africa, and its western summit, the Masai "Ngaje Ngai," means "the House of God." It is associated with the purity of death in this story, while snow is also associated with purity and death, as well as dreams and their loss. The title of the story foreshadows Harry's death and suggests the subject of the story, which is the process of dying.
Snow and mountain imagery come together as symbols of dying in Harry's first flashback, memories of hiking on a mountain in Bulgaria:
And it was snow they tramped along in until they died that winter.
A snowy mountaintop memory is described in idyllic terms:
Where they ran down the glacier above the Madlenerhaus, the snow as smooth to see as cake frosting and as light as powder and he remembered the noiseless rush the speed made as you dropped down like a bird.
But snow is also the ominous, stained harbinger of death:
The deserter came with his feet bloody in the snow.
They walk on
the sleigh-smoothed urine-yellowed road.
Snow represents loss too, as it is associated with gambling losses Harry suffers and his loss of his dream of writing.
Harry recalls himself traveling on horseback on the mountains at night, themselves another symbol of death. The mountains are clear, sharp, pure, and beautiful:
The mountains, the clear sharpness of the peak in the evening light and, riding down along the trail in the moonlight, bright across the valley.
At the end of the story, after he has died, Harry believes he is in the mountains and finally seems to be heading for the top of Kilimanjaro, the home of God:
There, ahead, all he could see, as wide as all the world, great, high, and unbelievably white in the sun, was the square top of Kilimanjaro. And then he knew that there was where he was going.
The title thus refers to what happens at the end of the story, when the dying Harry, who had done good deeds in his life, such as giving away his own morphine to relieve the pain of another soldier in World War I and protecting his wife by not telling her he doesn't love her, ascends to the snowy, mountaintop purity of death.