The ever increasing enrollment numbers and the corresponding dwindling educational resources in public schools have challenged the Ministry of Education in Malawi to introduce an instructional innovation (TALULAR) based on the use of locally available resources for teaching and learning. The purpose of this study was to determine: (i) whether, and to what extent, the perceived characteristics of innovations and teachers' demographic and employment variables are useful in predicting the implementation of TALULAR, and (ii) the extent to which TALULAR has been implemented by secondary school science teachers in Malawi. Rogers' (2003) diffusion of innovations theory provided the theoretical framework for the study. Using stratified random sampling, 269 science teachers, representing a response rate of 77%, provided data for this study. Among other findings, multiple regression analysis revealed that collectively, the perceived innovation characteristics are significant predictors of TALULAR implementation. The results further revealed that perceived relative advantage and perceived observability in terms of others' use are the two most important predictors of TALULAR implementation, and that implementation of the innovation by science teachers is at a moderate level. These findings might contribute to a deeper understanding of science teachers' perceptions of using the innovation and may aid change agents and agencies in planning a successful nation-wide diffusion campaign to ensure that all teachers not only adopt, but more importantly, implement the innovation in the classroom.