Designed for 3- and 4-year-old disadvantaged children and their parents, a mobile unit consisting of a renovated school bus turned classroom is described which travels to three areas daily for a 2-hour period. The program for children is designed primarily for developmental skills--visual, sensory, auditory, and cognitive. Activities emphasize language and concept development, the development of a positive self-image, and enrichment experiences. A program for parents operating concurrently includes home visits and contacts, group meetings, newsletters and homework, book, picture, and toy lending libraries, and a "teaching tiny tots" lesson plan. Results are reported which exceed expectations in language and measured IQ gains as well as in personal and social development. Parents gained in knowledge of child growth and development. Appendices provide information on approximate costs for operation of a mobile classroom and on floor plans. (LH)