Piączyn was formerly part of the German Empire. In the German Empire, the place was called NN.
The place is now called Piączyn and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Piaczyn | Russian Empire | Plock | 1914 |
| Piączyn | Poland | Płock | 1919 |
| NN | German Empire | Schröttersburg | 1939 |
| Piączyn | Poland | Płock | 1945 |
| Piączyn | Poland | Płock | 1992 |