Mycoacia angustata is a species of tooth fungus in the family Meruliaceae.

The specific epithet angustata refers to the narrow spores.

The spines are crowded close together, numbering about 3 or 4 per millimetre, and are about 1 mm long.

Mycoacia angustata is a wood-decay fungus, and grows on decaying wood.

The type collection was made in Bawangling Nature Reserve, Hainan Province.