The collision occurred shortly after 9.30am on a railway crossing for “reasons that are currently unknown,” police said in a statement.
The lorry driver and one passenger “suffered a shock” and were taken to hospital to be checked out. The train driver and all passengers were uninjured, said the statement.
However a police spokesperson told 20 Minutes that one person had been injured and the seriousness of those injuries was unknown.
The line between Horgen and Au will remain closed until around 4pm, according to Swiss federal railways (SBB).
Trains between Zurich and Chur and regional services between Zurich and Wädenswil are currently suspended.
International services between Zurich and Feldkirch in Austria are diverted via Winterthur.
Photo: Zurich cantonal police