Stevenson has stated that the story was inspired by a detailed map he drew from his imagination. This map, Stevenson wrote in an essay called "Treasure Island," "was elaborately and (I thought) beautifully coloured; the shape of it took my fancy beyond expression; it contained harbours that pleased me like sonnets; and with the unconsciousness of the predestined, I ticketed my performance 'Treasure Island.'"

The more Stevenson studied this map of his creation, the more his imagination expanded. First, he could see the vegetation of the island. Then the island became peopled in his mind's eye, and their stories began to appear. "It was to be a story for boys," Stevenson wrote; and with excitement and ease, he produced the first fifteen chapters in as many days. But then the inspiration disappeared—the author claims that he was at a very low point in his life at this time. He was thirty-one and had yet to make a salary on his own. He was supported by his father, and he wanted to write something that not only would make money but would please his father. Much of his writing up to this point Stevenson referred to as a failure; he was afraid that this current story he was working on would become one too.

Stevenson took a break from his work and went on a short vacation. Upon arriving at his destination, he sat down at a desk, determined to free himself from his despair. With great discipline, he started writing again. "And in a second tide of delighted industry," Stevenson wrote, "I finished 'Treasure Island.'" The book turned out to be a huge success for Stevenson, bringing both money and fame. It was published first as a magazine serial before being produced as a book in 1883. But that is not the end of the story. When Stevenson sent his manuscript to his publisher, the map, which had inspired the pirate story, was missing. It was never found. Stevenson had to create another map, "but somehow it was never 'Treasure Island' to me," Stevenson wrote.