The goals of the research were to inform whether the theory of planned behavior (TPB) is a valid model to explain Indonesian preservice teachers' (PSTs) use of information and communication technology (UICT) during teaching practices, to report best factor affecting PSTs' UICT during teaching practices, and to elaborate differences regarding UICT during teaching practices in terms of demographic information, gender, major, university, and information and communication technology (ICT)-based courses. The sample of this study was 1,133 PSTs from three Indonesian universities who completed a 24-item printed questionnaire of four constructs: behavioral beliefs (BB), normative beliefs (NB), control beliefs (CB), and UICT. Using partial least square-structural equation modeling (PLS-SEM), the results informed that the TPB is a valid model to help explain Indonesian PSTs' UICT during teaching practices. All constructs (BB, NB, and CB) significantly predict UICT during teaching practices where NB is reported to be the strongest predictor ([beta] = 0.354). There are no significant differences in terms of genders and ICT-based courses; however, significant differences are indicated in terms of majors and universities.