The A475 leaves Lampeter southwestwards from a junction with the A482 and passes through the hamlet of Pentre-Bach and the village of Llanwnnen, where it is crossed by the B4337 Llanrhystud to Edwinsford road. It passes through the villages of Dre-Fach and Cwmsychbant, then is crossed by the B4459 Talgarreg to Pencader road. The road continues to Pren-Gwyn and a junction with the B4476 road to Landysul. At Horeb the A475 is crossed by the A486 New Quay to Saron road. The road passes through Penrhywllan, Aber-banc and Llandyfriog, and reaches Newcastle Emlyn town centre after a roundabout junction with the B4571 and B4333 roads. After crossing the River Teifi into Carmarthenshire the road ends at a junction with the A484 in Water Street.
On 11 September 2001 a council lorry collided with a school bus near the Horeb crossroads. A number of children and three adults were treated for shock and minor injury, but no one was seriously injured. In the same year a young couple died when their car left the road near Lampeter. A review of speed limits was called for in 2013 following an accident on the road, which was referred to by a local driver as "a death trap". The A475 was classed by the Road Safety Foundation in 2011 as a Low-medium risk road; the classification was increased in 2014 as Medium risk.