Bedtime problems and frequent night wakings are common sleep problems in infants and toddlers, affecting 20 to 30% of young children. Such problems, categorized as behavioral insomnia of childhood (BIC), lead to insufficient sleep, which contributes to multiple domains of child dysfunction. Behavioral treatments of BIC, such as extinction and positive routines are introduced, and supporting evidence is reviewed. Critical factors in developing a successful treatment plan include conducting a detailed assessment, collaboratively developing a plan that starts where the family is, and providing support between sessions. A case of a 3-year-old girl with BIC illustrates how treatment helped her to develop healthy sleep habits and taught her to sleep independently via graduated and standard extinction. (C) 2010 Wiley Periodicals, Inc. J Clin Psychol: In Session 66:1195-1204, 2010.