Considerable research suggests that standardizing curricular materials can undermine teachers' ability to facilitate learning. Nonetheless, U.S. school districts' curriculum guides have become increasingly standardized, with teachers being required to follow predetermined pacing calendars indicating which standards to teach during specific months, weeks, or days. Pressure to comply with curriculum guides and their associated pacing calendars is a particular concern among beginning teachers. Given these issues, this investigation explored three first-year teachers' experiences with curriculum guides and pacing calendars in the primary grades. Although curriculum guides helped participants learn the curriculum and decide how to sequence the content, rigid campus policies that required participants to follow pacing calendars led to uncomfortable professional dilemmas and teacher resistance. Findings suggest that despite novice teachers' fears of being reprimanded and their lack of professional knowledge, they carry out "principled resistance" to standardized curricular mandates according to their understanding of students' needs and their deeply held convictions about what is best for the children in their classrooms.