<p style="text-align: justify;">This study investigated the extent to which demographic variables, principal support and teacher self-efficacy contribute to the collective teacher efficacy. In the study, a non-probability purposive sample was used, which included 761 teachers working in compulsory primary schools in all parts of the Republic of Croatia. The first part of the administered online questionnaire provided data on sociodemographic characteristics of the respondents, while in the second part, the following scales were used: The Principal Support Scale, The Teacher Sense of Teacher Efficacy Scale and The Collective Teacher Efficacy Scale. The results of the performed regression analyses show that: 1) the demographic variables - workplace, promotion to a higher rank and principal support have a predictive value in explaining teachers’ self-efficacy; 2) an average number of students per class, promotion to a higher rank, principal support, teacher engagement and teaching strategies have a predictive value in explaining collective teacher efficacy. The findings of this study will be discussed in terms of their potential impact and future research.</p>