Speech and language evaluations of 116 patients, ages 2 months to 29 years, with Cornelia de Lange syndrome (CdLS), also known as Brachmann-de Lange syndrome, were conducted to survey speech and language skills and to ascertain the prognostic value of related variables. These patients were evaluated at conferences of the CdLS Foundation. The data from these evaluations were then analyzed using the database program of Paradox 3.5. The findings indicated that 53% of the children who were 4 years or older combined 2 or more words into sentences and 33% had no words or only 1-2 words. Four percent were judged to have language skills within normal to low-normal limits. Children who were not talking at all or who were severely delayed in language skills had at least one of the following characteristics: birth weight under 5 lbs.; a reported diagnosis of moderate-to-severe hearing impairment; upper limb malformations; poor abilities to relate socially; and/or severe motor delays, e.g., they did not sit up until after age 25 months or did not walk until after 35 months.