It is a large evergreen shrub or small tree growing to 12 m (39 ft) in height, with leathery leaves up to 30 cm (12 in) in length.

The felted undersides are a grey or buff colour.

The flowers, borne in trusses in spring, are bell-shaped, pale to deep yellow, with a purple basal blotch.

[2] In cultivation in the UK Rhododendron macabeanum has gained the Royal Horticultural Society's Award of Garden Merit.

[2][3] It is hardy down to −10 °C (14 °F) but requires a sheltered spot in dappled shade, and an acid soil enriched with leaf mould.