The 37-year-old engineer suffered extensive skull and rib injuries in the attack by two men in Potsdam, eastern Germany.
About 100 foreigners have been killed in attacks by neo-Nazis since German reunification in 1990.
The racist attacks have been most common in the formerly communist east.
Prosecutors in Potsdam have offered a 5,000-euro (£3,460; $6,052) reward for information leading to the arrest of the attackers.
Source: BBC News
