Trętowo-Pełzy was formerly part of the German Empire. In the German Empire, the place was called Tretowo Pelzy.
The place is now called Trętowo-Pełzy and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Tretowo Pelzy | Russian Empire | Cehanov | 1914 |
| Trętowo-Pełzy | Poland | Ciechanów | 1919 |
| Tretowo Pelzy | German Empire | Zichenau | 1939 |
| Trętowo-Pełzy | Poland | Ciechanów | 1945 |
| Trętowo-Pełzy | Poland | Ciechanów | 1992 |