Early childhood is a ripe time for students to begin learning science, but due to certain constraints, this instruction is not happening as frequently as it should. This mixed-methods, multiple case study examined how two teachers implemented an early childhood science curriculum, the "Young Scientist Series." The teacher participants were two early childhood teachers, and student participants were three groups of 4 to 6-year-olds they taught for eight weeks. The study investigated how the teachers' pedagogical decisions affected their students' process skills acquisition and attitudes toward science. It specifically examined how the teachers made choices about what to include, change, omit, and add to the lessons. It also analyzed the levels of inquiry present in the lessons (structured, guided, or open). Quantitative data were collected from the teachers through questionnaires, checklists, and observations, and qualitative data were gathered through interviews. Student data were quantitative. Their science process skills and attitudes towards science were assessed with two age-appropriate instruments, the Science Learning Assessment and the Puppet Interview Scale for Competence in and Enjoyment of Science. Findings showed that the students of the teacher who followed the curriculum more closely and employed more structured inquiry did not grow in their process skills, and their attitudes followed a normal distribution. The students of the teacher who followed the curriculum more leniently and employed more guided inquiry grew in their process skills in significant ways. Their attitudes followed a negatively skewed distribution, reflecting that a majority of the students scored very highly on the attitude assessment. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]