This study was designed to develop an instrument that would measure preservice teachers' belief efficacy in teaching environmental education (EE). This belief efficacy includes a person's perception of ability to perform the behavior (self-efficacy) and a person's expectation that a specific behavior will result in desirable outcomes (outcome efficacy). It was hypothesized that preservice teachers (the respondents in this preliminary study) would display lack of confidence in their own abilities to teach EE concepts (negative self-efficacy beliefs), but would show confidence that student learning in EE can be improved by effective teaching (positive outcome expectancy beliefs). The Environmental Education Efficacy Belief Instrument (EEEBI) containing self-efficacy belief and outcome expectancy scales was developed and administered to 40 preservice elementary teachers enrolled in a science/mathematics methods course. Results confirm the hypothesis as stated and support the need to address training in EE teaching among preservice teachers by either integrating environmental themes across disciplines or through a separate course. A copy of the EEEBI is included and four tables display the results. (Contains 13 references.) (LL)