An instructional strategy was investigated that addressed the needs of deaf and hard of hearing students through a conceptually based sign language vocabulary intervention. A single-subject multiple-baseline design was used to determine the effects of the vocabulary intervention on word recognition, production, and comprehension. Six students took part in the 30-minute intervention over 6-8 weeks, learning 12 new vocabulary words each week by means of the three intervention components: (a) word introduction, (b) word activity (semantic mapping), and (c) practice. Results indicated that the vocabulary intervention successfully improved all students' recognition, production, and comprehension of the vocabulary words and phrases. (Contains 8 figures and 4 tables.)