| Perlbach | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Germany |
| Subdivision Type2: | State |
| Subdivision Name2: | Bavaria |
| Subdivision Type3: | Districts |
| Subdivision Name3: | Straubing-Bogen and Cham |
| Subdivision Type4: | Reference no. |
| Subdivision Name4: | DE: 152294 |
| Length: | 26.21 km |
| Source1 Location: | south of Zinzenzell |
| Source1 Coordinates: | 49.067°N 12.577°W |
| Source1 Elevation: | over |
| Mouth Location: | west of Wiesing from left and south into the Regen |
| Mouth Coordinates: | 49.1768°N 12.4768°W |
| Mouth Elevation: | under |
| River System: | Danube |
| Progression: | Regen → Danube → Black Sea |
| Basin Size: | 82.43 km² |
| Custom Label: | References |
The Perlbach is a river in Bavaria in the provinces of Lower Bavaria and Upper Palatinate, which drains into the Regen west of Wiesing in the borough of Roding in the Upper Palatine county of Cham.
On the Lower Bavarian side and up to Falkenstein the Perlbach is still called by its original name of Miethnach.[1] That the name Miethnach is the older, is indicated by the name of the hamlet Mietnach am Perlbach (between Marienstein and Trasching), west of the Zinzenberg.
The Perlbach rises in the Lower Bavarian county of Straubing-Bogen south of Zinzenzell between Geraszell and the Edenhof. It flows, roughly speaking, northwestwards; its upper course more or less constantly, while its lower course runs in a large, roughly semi-circular arc towards the southwest and back. Early on it enters the Upper Palatine county of Cham, in which it remains until it reaches its mouth near Wiesing and empties into the Regen.
Its larger tributaries are the left-hand Geißbach which joins it near Völling, the left-hand Urbachl near Au and the longest, last and right-hand Neudecker Bach just after Trasching.