The nutlet morphology of 53 taxa (24 genera) of Lamiaceae in Korea was examined using stereo microscopy (SM) and scanning electron microscopy (SEM) in order to evaluate their diagnostic values and systematic implications. The nutlet shapes are variable: Globose to sub-globose, ellipsoid to broadly ellipsoid, ovoid, and obovoid to broadly obovoid. The colors of nutlet were yellowish brown, brown, and black. The size of nutlets of the examined taxa range from 0.58 to 3.35 mm in length and from 0.40 to 2.25 mm in width; the smallest one was found in Dysophylla stellata, while the largest was measured in Ajuga spectabilis. Eight epidermal cell types of the nutlet surface can be distinguished: Reticulate I-II, tuberculate, retangular I-II, rugulate I-II, and striate. The trichomes on the nutlet were found in both Agastache rugosa and Meehania urticifolia. Systematic implications of the nutlet micromorphological characters were also briefly discussed, in comparison with earlier taxonomic systems. - This project was supported by the Korea National Arboretum (No. 201720334).