Objective: Teachers' attitudes toward inclusion are often based on the practical implementation of inclusive education rather than a specific ideology and understanding of inclusiveness. This study aimed to identify the factors associated with primary school teachers' attitudes towards inclusion of students with all disabilities in regular schools. Method: Seventy four primary school teachers participated in a cross-sectional survey conducted in Western Australia. Teachers' attitudes and efficacy toward integration of students with disabilities were measured using the Opinions Relative to Integration of Students with Disabilities scale and Bandura's Teacher Efficacy scale respectively. Results: Four teacher attributes-age, gender, teaching self-efficacy and training collectively explained 42% of the variability in teachers' attitude toward including students with disabilities. Conclusion: The current study further contributes to the accumulation of knowledge that can unpack the complex pattern of factors that should be considered to promote positive attitudes towards inclusive schools.