It depicts his younger sister, who frequently sat for Schiele as his model in his formative years. He was close to Gerti, and to some extent the painting shows a softer and more gentle side than many of his later paintings of young women.

In 1909, Schiele's quality was just beginning to be recognised by the public; he had had his first exhibition the previous year. He was still strongly influenced by Gustav Klimt, and the two men collaborated at times. However, Schiele was rapidly developing his own style, and Portrait of Gerti Schiele demonstrates this while retaining clear Klimtian influences.

The softness in the painting shows Schiele's move away from simple emulation of Klimt's style, as do the large areas of flat colour accented in silver. Schiele was beginning to use a quieter, less elaborate style than that usually favoured by his mentor. It gives the impression of a two-dimensional representation of a clay or plaster sculpture, with a restrained and dry palette of colours, especially golds and bronzes. This suggests maturity and even decay rather than still-blooming youth.

Portrait of Gerti Schiele, created on canvas with oil and pencil, together will small amounts of gold and silver, is now owned by the Museum of Modern Art in New York City. It was passed to MoMA by Ronald Lauder, the founder of the same city's Neue Galerie, and the painting has been hung on loan there for an extended period.