One of the characteristics of teaching chemistry through inquiry is that teachers need to encourage students to design their experimental procedures. Although the benefits of inquiry teaching are well documented in the literature, few teachers implement it in schools. The purpose of this study was to develop a guided-inquiry scale (GIS) to measure teachers' beliefs about implementing guided-inquiry labs in secondary schools. Construction of this guided-inquiry scale was based on a model with three dimensions: the value of guided-inquiry labs, limitations of cookbook-style labs, and implementation issues with guided-inquiry labs. Data were collected from 200 Hong Kong chemistry teachers. They responded to the GIS items using a seven-point Likert scale. The GIS data were of adequate reliability. Confirmatory factor analysis indicated that a good fit exists between the hypothesized model and data. Both users and nonusers of guided-inquiry labs valued this kind of lab work and recognized the limitations of cookbook-style labs; however, nonusers tended to believe that students dislike guided inquiry and it is not feasible for students to design experiments. The length of chemistry teaching experience and the level of student ability did not influence teachers' beliefs about implementing guided-inquiry labs. (Contains 5 tables.)