Published in 1785 alongside the Piano Sonata No. 14 in C minor. According to Mozart's own catalog of works, the sonata was composed on October 14, 1784, and the fantasy on May 20, 1785. Since fantasies originally served as introductory pieces, it is believed that this work was composed as a prelude for the sonata's publication. Although these two pieces are often treated as a set even today, considering that Mozart himself sometimes performed only the fantasy, it is reasonable to regard them as two independent works.

It was dedicated to Therese von Trattner, the wife of the landlord of the house Mozart rented at the time (the so-called 'Figaro House'). She was also one of Mozart's piano students.

The work frequently modulates and develops freely, befitting the name 'fantasy,' and can be divided into five sections based on tempo changes: Adagio, Allegro, Andantino, Più Allegro, and Adagio. The initial Adagio can be further divided into two parts: a somber C minor and a brighter D major. This opening theme, which seems to rise from the earth, returns at the end, concluding the work and serving as a bridge to the C minor sonata.