The present invention pertains to: a saturated ring-condensed dihydropyrimidinone or dihydrotriazinone compound having ROR? antagonist activity or a pharmaceutically acceptable salt thereof； a pharmaceutical composition containing same； and a pharmaceutical use thereof. Provided are: a compound of formula [I] or a pharmaceutically acceptable salt thereof； a pharmaceutical composition containing same； and a pharmaceutical use thereof. [In the formula, the respective substituent groups are as defined in the description of the present application.]
