The purpose of this paper was to determine the readiness of kindergarten teachers in Bulgaria in anticipation of impending inclusion-driven reforms in the education system. Data on 922 kindergarten teachers' attitudes towards inclusion across three dimensions (cognitive, affective, and behavioural), their concerns, and self-efficacy were analysed. Overall, teachers reported being willing to adapt their behaviour to promote inclusion in their classroom, despite not feeling particularly positively about inclusion. Inclusion-related training, which is critical for teachers to meet the demands of reforms, was a robust, positive predictor of teachers’ attitudes across all three dimensions. •This paper examined the attitudes towards inclusion of 922 teachers in kindergartens in Bulgaria across three dimensions (cognitive, affective, behavioural), their concerns, and self-efficacy in this regard.•Teachers were most likely to hold negative affective attitudes and positive behavioural attitudes towards inclusion.•Inclusion-related training significantly predicted positive attitudes towards inclusion across cognitive, behavioural, and affective domains.•The findings accentuate the importance of continuous professional development for teachers already teaching in the system in fostering more positive attitudes towards inclusion.