A new neoclerodane, (12R)-epi-teuscordonin [1] has been isolated from Teucrium bicolor. The boat conformation of ring B and the configuration at C-12 in 1 were established by nOe experiments. The known diterpenoids montanin C, teucvin, 12-epi-teucvin, teupolin I, 12-epi-teupolin I, and (12S)-teucrin H-2 were also isolated from the extract. Montanin C [2] was found to be moderately toxic in the brine shrimp bioassay.