This research evaluated the effectiveness of training and educating preservice teachers to understand and implement developmentally appropriate practices for children birth to age 5. Data from 803 participants were collected over a 3-year period at a university with a laboratory child care program associated with an undergraduate degree in child and family development. Findings supported the strength of a 17-item scale that was developed to assess gains in knowledge and skills in a multicourse sequence over the 3-year period. Knowledge and skill increased significantly in all three courses from pre to posttest. The magnitude of change decreased for knowledge and increased for skill as students progressed through the three-course sequence. Knowledge gains were greatest in Course 1 and smallest in Course 3. However, skill gains were greatest in Course 3 and smallest in Course 1. A multivariate analysis of all six time points, involving students who completed the survey in all three classes, indicated that knowledge and skills increased in each class with the greatest increase in skills in Course 3. The laboratory courses were an effective means of promoting understanding and implementation of developmentally appropriate practices in preservice teachers. Implications for improving early childhood teacher education are discussed.