The leaves of Indigofera angustifolia are pinnate with narrow, linear leaflets that have sunken midribs and margins slightly rolled under. There are three pairs of leaflets and a terminal one. The rounded leaflet tip curves down slightly and is mucronate, i.e. a tiny, pointed protrusion is usually present.
Leaflet surfaces are shiny although coarse, some red colouring visible in the photo near the margins. The lower surfaces of the leaflets are felted (Bond and Goldblatt, 1984; Privett and Lutzeyer, 2010; JSTOR; iSpot).