The 36 year old man went trekking on the mountainous area of Vradeto, Zagorohoria, on Monday morning and since then there was no sign of him.
He was staying at Papigo village with a friend who worried when he did not return from his run. His friend therefore went to the police, the man was declared missing on Tuesday and units have deployed to locate him.
Vradeto lies at a height of 1340m on Mt Tymphe in the Pindus mountain range. It is the highest of the 44 villages of Zagori.
Fire Brigade special rescuers unit (EMAK) has eye contact with the 36 year old German.