Leptospermum grandiflorum is a densely-branched shrub that typically grows to a height of or more and has rough bark on older branches and whitish young stems. The leaves are thick, greyish green, elliptical to broadly egg-shaped with the narrower end towards the base, mostly long and wide, tapering to a short, often twisted
petiole. The flowers are arranged singly on short side branches on a
pedicel about long and are about in diameter. The
floral cup is dark and wrinkled, about long and more or less
glabrous. The
sepals are broadly egg-shaped to round, long and fall off as the fruit develops. The
petals are white, about long and the
stamens long. Flowering occurs from February to April and the fruit is a
capsule wide that remains on the plant. ==Taxonomy and naming==