Emergency services were called to the accident on the A470 south of Llandinam, on the Newtown to Llanidloes road.
Fire crews from Newtown and Montgomery were joined by Welsh Ambulance and Dyfed Powys police, who closed the road.
Police officers warned drivers to find other routes for their journey.
Drivers had to make long diversions around the crash.
Newtown fighters had just returned from a property fire when the crew was called out to the accident.