An in-depth case study of teachers' use of image processing (a state-of-the-art computer technology used by research scientists) in biology, earth science, and physics classes within one high school science department explored issues surrounding technology implementation. The study, conducted within a districtwide, schoolwide, and classroom context, explored four areas related to the teacher's adoption of image processing: (a) teachers' background with computers outside of instructional use, (b) teachers' attitudes toward educational technology and insights gained from their experience using computers within the science curriculum, (c) training and perceived influence of district and school administrators, and (d) teachers' classroom and computer lab practices. The following factors were deemed critical in teachers' decision to use or not use image processing with their students: (a) time to thoroughly explore and master the technology so they could use it with students to explore science concepts; (b) classroom management skills specific to technology use; (c) perception of the teaching value of the technology; (d) perception of the reasonableness of administrators' expectations for technology use; and (e) understanding of how to implement inquiry-based science teaching, independent of technology issues. These factors have implications for how to help teachers use computer technology to teach high school science.