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