Is the name 'Teschko' Italian?

Yes, Teschko can be an Italian name.

Specifically, the name functions as a proper noun. It is a rare surname which has the most chances of being found in the parts of northern Italy bordering Austria or Switzerland. It traces its origins back to the Italian word tedesco for "German."

The pronunciation will be "TEY-shko" for the surname and "tey-DEY-sko" for the source.