In 1989, the IEA Computers in Education study collected data on computer use in elementary, lower- and upper secondary schools in 22 educational systems. The data collection included attitude measures for principals of computer-using as well as non-using schools and for teachers of computer education courses and teachers of existing subjects. The latter group consisted of computer-using as well as non-computer using teachers from mathematics, science and mother tongue. This article raises the question to what extent attitudes play a role in the process of integrating computers in the existing curriculum. The article mainly focuses on lower secondary schools from 14 countries and shows that attitudes of principals and teachers of existing subjects vary greatly, between as well as within countries. Moreover, it can be shown that attitudes covary in a meaningful way with the extent to which computers are used by computer-using teachers.