Geo Milev studied in Sofia and later in Leipzig where he was introduced to German Expressionism. His university thesis was on Richard Dehmel. Beginning in 1916 he fought in the World War I, where he was severely injured. After recuperating in Berlin he began to collaborate with the magazine Aktion. Upon his return to Bulgaria he started to publish the Bulgarian modernist magazine Везни (Scales), in Sofia. He contributed as a translator, theatre reviewer, director and editor of anthologies.
On May 15, 1925 Geo Milev was taken to the police station for a "short interrogation" from which he never returned. His fate remained unknown for 30 years. In 1954 during the trial of General Ivan Valkov and a group of physical executioners one of them confessed where and how the reported missing had been executed and buried. Geo MIlev was strangled and then buried in a mass grave in Ilientsi, near Sofia after the reprisals following St Nedelya Church assault. The repressive government used that as an excuse for murdering progressive intellectuals. His skull was found in the mass grave. His body was identified due to the glass eye he was wearing after he lost his right eye in World War I.
He published his most famous poem September in his magazine Пламък (Flame) in 1924. It describes the brutal suppression of the Bulgarian uprising of September 1923 against the military coup d'état of June 1923.