A variable valve device for an internal combustion engine comprises a first switching oil passage which is formed along an axial direction in one of a rocker shafts, the first rocker arm being switched to the first mode by applying oil pressure to a first rocker arm through the first switching oil passage, and a second switching oil passage which is formed along an axial direction in the other rocker shaft, a second rocker arm being switched to the first mode by applying oil pressure to the second rocker arm through the second switching oil passage. The first switching oil passage and the second switching oil passage are formed in a ladder shape in which the first switching oil passage and the second switching oil passage communicate via a plurality of relay oil passages.