This evaluation assessed the effect of Hale and Hardy's Helpful Health Hints preschool health education curriculum on the health knowledge of children ages three-six. The sample consisted of nine experimental preschool programs (n = 194) and three comparison preschool programs (n = 73). A picture identification test assessed children's pretest and posttest health knowledge of the five senses, safety, nutrition, dental health, personal responsibility, emotions, hygiene, and drugs/medicines. Posttest knowledge scores increased by 22% among experimental group preschool programs and 12% among comparison group preschool programs. Significant differences (p less than .01) were found between experimental and comparison group students. Findings provide direction in research efforts to define conditions in which preschool health education is optimally effective.