The current study aimed to uncover the underlying psychological traits of the environmental behaviour of Indonesian preservice biology teachers. A hypothesized model based on theoretical background and previous studies was established and tested on a total of 216 Indonesian preservice biology teachers in West Java province. Gender and education effects were also considered in the testing of the environmental-related psychological traits of Indonesian preservice biology teachers. Ten scales of the Environmental Attitudes Inventory (EAI) were used as the main research instrument, and semi-structured interviews were also conducted to uncover more the perceptions of Indonesian preservice biology teachers of the environment. Independent sample t-test, analysis of variance, correlation tests, and structural equation modeling (SEM) were used to answer the proposed research questions. The results revealed significant gender and educational year differences in several environmental scales. Moreover, the accepted model results from SEM indicated an acceptable statistical model of Indonesian biology teachers' environmental beliefs and found that two paths influence the self-reported environmental behaviour of Indonesian preservice biology teachers. Based on the model, environmental beliefs and intention were found to have direct effects on the self-reported environmental behaviour. The current study highlights the importance of developing courses that can improve preservice teachers' environmental beliefs and intention.