The purpose of this study was to investigate (a) what effect the use of interactive computer-based simulations (ICBSs), the use of laboratory inquiry-based experiments (LIBEs), and the use of combinations of an ICBS and a LIBE, in a conceptually oriented physics course, have on science teachers' beliefs about and attitudes toward the use of these learning and teaching tools, as well as the effect on their intentions to incorporate these tools in their own future teaching practices, (b) science teachers' attitudes toward physics and the effect that the use of ICBSs and/or LIBEs have on teachers' attitudes toward physics, and (c) whether teachers' beliefs have an effect on their attitudes and whether their attitudes have an effect on their intentions. A pre–post comparison study and the Theory of Reasoned Action (TRA) were used for this purpose. Results confirmed the TRA model that beliefs affect attitudes and these attitudes then affect intentions, and showed that science teachers' attitudes toward physics, the use of an ICBS, the use of a LIBE, and the use of a combination of an ICBS and an LIBE were highly positive at the end of the study. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 792–823, 2003