It is the tallest of the Gasteria species (even larger than its close relative to the east, Gasteria excelsa), with rosettes of light-green, sharp, stiff, spotted leaves, that are up to 1 meter long. The species name "acinacifolia" means "scimitar-leaves", and refers to how the smooth adult leaves curve, and end in a sharp point. The multi-branched inflorescence is often over a meter in height, with pink flowers and appears between September and December. The inflorescence is flat-topped (unlike that of Gasteria excelsa) and has racemes that spread horizontally. It can be confused with Gasteria excelsa to the east, but G.excelsa has thicker, wider, straighter, smoother, darker leaves, that have fewer spots and much sharper, heavily-serrated margins, as well as a more erectly branching inflorescence.