There is no unified view about how teachers' integration of information and communication technology (ICT) should be measured. While many instruments have focused on the technological aspects, recent studies have suggested teachers' pedagogical considerations, professional development, and emerging ethical and safety issues should be included when assessing teachers' ICT literacy. Using the performance standards created by the International Society for Technology in Education, a group of Taiwanese teachers developed equivalent items. After consulting expert panels and interviewing teachers, a scale was constructed. Using this instrument, 3729 teachers from grades 1 through 9 in Taiwan were sampled. Half of the data was analysed by exploratory factor analysis to find the underpinning structure, and the second half was analysed by confirmatory factor analysis to verify the subscales. The results confirmed six subscales for teachers' ICT integration: (1) information collection and preparation; (2) material production and troubleshooting; (3) communication and sharing; (4) planning, teaching and evaluation; (5) professional development and self-study; and (6) ethical, health and safety issues. Using two teacher attributes, school levels and course or degree obtained, the scale was further verified for its feasibility. The established scale examines the existing concerns for technology, pedagogy and professional development at once with a new addition of ethical and safety issues, which demand growing attention in teachers of future generation.