The soft, grass-like leaves of Kniphofia angustifolia grow tufted from the base, initially erect and angled up, then arching out. The dull blue-green to yellow-green blades are shallowly keeled on their lower surfaces, channelled on top. The margins and keels are smooth or slightly toothed. The inner leaves are taller, straighter and younger.
Leaf dimensions are from 40 cm to 70 cm long by only 2 mm to 3 mm wide.
The specific epithet, angustifolia, is derived from the Latin words angustus meaning narrow and folia meaning leaves, referring to the shape of the leaves (Pooley, 1998; iNaturalist).