Teachers’ readiness, knowledge and attitudes level towards inclusive education in mainstream schools were explored as they were tasked to carry out this responsibility.  They must ensure success of inclusive education which actually depended heavily on their readiness in inclusive classes, teachers’ knowledge level and attitude towards teaching inclusion classes.  This research study aimed to explore teachers’ readiness level in inclusive classes, teachers’ knowledge level and attitude towards teaching inclusive classes in primary and secondary schools in the district of Sibu, Sarawak. The sample size for this study consisted of 154 respondents. This study explored specifically into the teachers’ readiness, knowledge and attitude level towards inclusion in the classrooms. The method used for this research was descriptive survey approach.  Identified teachers involved directly in teaching and supervising students with special educational needs (SEN) in the inclusive classrooms were provided with survey questionnaire.  Fully completed questionnaire were collected from respective schools through self-collection, post or email.  The data collected was analysed for descriptive and inferential statistics, percentages, t-test and ANOVA using SPSS (version 22).  The outcome of the findings was discussed according to the objectives and research questions of the study.  This outcome of this study showed high readiness level among teachers, high knowledge level among teachers and positive attitudes of teachers toward inclusive education.  At the same time, the study also found out that there are strong positive correlation between teachers’ readiness, knowledge and attitude level.  Keywords: Inclusive education, readiness, knowledge, inclusion, special educational needs (SEN) students.