The 75-year-old Rau died last Friday of a long and grave illness.
The book can be signed until 2 February.
Rau, who was the German President from July 1999 to June 2004, was known for his maxim "to reconcile, not divide".
ZAGREB, Jan 30 (Hina) - The German Embassy in Zagreb on Monday opened abook of condolence over the death of former German President JohannesRau.
ZAGREB, Jan 30 (Hina) - The German Embassy in Zagreb on Monday
opened a book of condolence over the death of former German President Johannes
Rau.