Eupithecia horismoides is a moth in the Geometridae family. It is found in the regions of Araucania (Cautin Province) and Los Lagos (the provinces of Osorno, Llanquihue, and Chiloe) in Chile. The habitat consists of the Northern Valdivian Forest and Valdivian Forest Biotic provinces. The length of the forewings is about 14–16 mm for males and 14.5-16.5 mm for females. The forewings are brown, with irregular ochraceous brown cross lines. The hindwings are greyer than the forewings. Adults have been recorded on wing in October and from December to March.