The goal of this study was to examine the effect of early childhood mental health consultation on teacher sensitivity over time, taking into account specific characteristics of early childhood mental health consultation that contribute to change in teacher sensitivity. One-hundred and forty-one early childhood teachers, serving economically disadvantaged 3- and 4-year olds in the state of Arkansas participated in this study. All child care sites and preschool programs participating in the study received early childhood mental health consultation through the Community Mental Health Partnership with Early Childhood Programs over a period of 3 years. Findings from this study suggest that teachers participating in an early childhood mental health consultation intervention made significant gains toward sensitivity as compared to teachers' initial levels of sensitivity. Quality of early childhood mental health consultation and teachers' experiences of early childhood mental health consultation predicted change in sensitivity as measured by more positive interaction, less detachment, and less punitiveness. Teachers with less classroom experience and lower sense of efficacy at the start of the study evidenced the greatest change toward sensitive caregiving practices over the course of the intervention. Findings suggest that early childhood mental health consultation may be a promising professional development intervention for teachers in early childhood settings. [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.]