Understanding how teachers perceive the implementation of new teaching practices is important, since they are the ones deciding whether an innovation will be sustainable in the classroom. In this longitudinal study, elementary school teachers (N = 73) successively implemented three evidence-based innovations (1: an assessment tool; 2: feedback material; 3: differentiated reading material) into their reading classrooms over one school year. For each innovation, we examined the interplay of prior teaching-related attitudes, innovation-specific perceptions that were developed during the implementation, and the perceived implementation success at the end of the school year. For all three innovations, path analyses showed that important predictors for innovation-specific perceptions and implementation success were teachers' congruent prior attitudes. Implementation success was less likely predicted by innovation-specific perceptions, which showed innovation -dependent patterns. Our findings indicate that sensitizing teachers early to evidence-based practices will help promote these practices' successful implementation.