Pycnarmon nebulosalis is a moth in the family Crambidae.

The forewings are brown, except for some white specks near the base, a patch in the cell, an apical patch and a spot at the middle of the outer margin.

There are traces of a dark waved antemedial line and there is a dark-edged white discocellular spot, as well as a dark-waved postmedial line defined by white and bent outwards between veins 7 and 4.

The hindwings have a white basal area and a fuscous discocellular spot.

There is an irregularly waved postmedial line defined by white and with some diffused fuscous on its inner edge and there is a dark marginal line with some dentate white marks on its inner edge.