Forty-two children (29 boys and 13 girls), ages 3-10 years, were referred from the caseloads of clinical speech-language pathologists for suspected childhood apraxia of speech (CAS). According to results from tests of speech and oral motor skills, 22 children met criteria for CAS, including a severely limited consonant and vowel repertoire, difficulty sequencing syllables, and inconsistent and unusual errors. Family pedigrees for these children were constructed through parent interviews and direct testing of nuclear family members. Familial aggregation for speech-sound and language disorders was demonstrated with 86% reporting at least one nuclear family member affected. Based on parent report, 13 of the 22 children (59%) had at least one affected parent. However, CAS was evident in only two siblings of probands with CAS and two probands with other speech-sound disorders. Based on testing, overall affection rates of speech-sound/language disorders were higher in families of children with CAS than in families of children with other speech-sound disorders. Mothers of children with CAS demonstrated a higher affection rate than mothers of children with other speech-sound disorders. A sex-related threshold model of transmission was also supported with brothers more often affected than sisters for male probands only. If our inclusionary criteria for CAS are valid, these findings support a general verbal trait deficit hypothesis.