Many children exhibit challenging behavior even in preschool. Recent reports have suggested that behavior problems, language skills, and academic delays are interrelated and perhaps mutually causal mechanisms, each adversely influencing the other. Language difficulties lead to behavior problems, behavior problems lead to academic delays, and academic delays lead again to behavior problems, all leading to early school failure. Little is known about this relationship in young children, 18 to 60 months of age, relative to what is known in older children, particularly in high risk samples. This investigation examined these relations among early measures of behavior problems (i.e., externalizing and internalizing), receptive and expressive language, and early literacy skills in a multisite sample of young children at risk for challenging behavior. Additionally considered were two cohorts of children specified by age and the language most heard at home. Using the severity and stability of behavior problems as a primary analytic factor, results for children who most heard English at home indicated: (a) distinct over-time patterns in behavior problems and (b) mixed covarying relationships to lower language proficiency and lower early literacy developmental outcome patterns. Results for a small sample of children, who most heard Spanish at home, when compared to the English group, indicated no differences in language proficiency on tests administered in English and Spanish, but lower outcomes on early literacy measures administered in English. Implications and the need for further research are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]