Scriabin gave the final concert of his lifetime on 2 April 1915 in St. Petersburg, performing a large program of his own works. He received rave reviews from music critics such as Ossovsky, who called his playing "most inspiring and affecting", as well as Ellen von Tiedeböhl, who proclaimed "his eyes flashed fire and his face radiated happiness". Scriabin himself wrote that during his performance of his Third Sonata, "I completely forgot I was playing in a hall with people around me. This happens very rarely to me on the platform."
Scriabin returned triumphantly to his apartment in Moscow on 4 April, when he noticed a resurgence of the little pimple on his upper right lip. He had mentioned the pimple as early as 1914 while in London. His temperature rose, he took to bed and cancelled his Moscow concert for 11 April. The pimple became a pustule, then a carbuncle and again a furuncle. Scriabin's doctor remarked that the sore looked "like purple fire". His temperature shot up to 41 °C (106 °F) and he was now bed-ridden. Incisions were made on 12 April, but the sore had already begun to poison his blood, and the composer became delirious. Bowers writes: "intractably and inexplicably, a simple spot had grown into a terminal ailment." On 14 April 1915, at the age of 43 and at the height of his career, Scriabin died in his Moscow apartment, on the same day his lease expired.
While Scriabin wrote only a small number of orchestral works, they are among his most famous, and some are performed frequently. They include a piano concerto (1896), and five symphonic works, including three numbered symphonies as well as The Poem of Ecstasy (1908) and Prometheus: The Poem of Fire (1910), which includes a part for a machine known as a "clavier à lumières", known also as a Luce (Italian for "Light"), which was a colour organ designed specifically for the performance of Scriabin's tone poem. It was played like a piano, but projected coloured light on a screen in the concert hall rather than sound. Most performances of the piece (including the premiere) have not included this light element, although a performance in New York City in 1915 projected colours onto a screen. It has been claimed erroneously that this performance used the colour-organ invented by English painter A. Wallace Rimington when in fact it was a novel construction supervised personally and built in New York specifically for the performance by Preston S. Miller, the president of the Illuminating Engineering Society.
Scriabin's funeral, on 16 April 1915, was attended by such numbers that tickets had to be issued. Rachmaninoff, who was a pallbearer at the funeral, subsequently embarked on a grand tour of Russia, performing only Scriabin's music for the benefit of the family. It was the first time Rachmaninoff had publicly performed piano music other than his own. Sergei Prokofiev admired the composer, and his Visions fugitives bears great likeness to Scriabin's tone and style. Another admirer was the English composer Kaikhosru Sorabji, who promoted Scriabin even during the years when his popularity had decreased greatly. Aaron Copland praised Scriabin's thematic material as "truly individual, truly inspired", but criticized Scriabin for putting "this really new body of feeling into the strait-jacket of the old classical sonata-form, recapitulation and all", calling this "one of the most extraordinary mistakes in all music."