The regular schools of India are turning into inclusive ones following the directives of the Government of India, but for inclusive education to be successfully implemented, knowledge of teachers' attitude is important as they need to transform their teaching styles in order to cater to the needs of all children. This study explores the perspectives of in-service school teachers towards acceptance of students with special needs in regular classrooms, and teachers' concerns towards implementing inclusion. The sample comprised of 100 in-service teachers of mainstream Government schools of the city of Kolkata (India) selected through random sampling technique. A comparison was made between the perspectives of 50 teachers of primary section and 50 teachers of secondary section. The Sentiments Attitudes and Concerns towards Inclusive Education Revised (SACIE-R) Scale (Forlin, Earle, Loreman, & Sharma, 2011) and a structured questionnaire made by the investigators were administered. Factors affecting attitude towards inclusive education and training needs of the teachers were also studied. Results revealed moderate positive attitude among the teachers towards acceptance of students with special needs in their classes. The teachers of secondary section were found to have higher concern levels than the teachers of the primary section with regard to implementing inclusive education. Besides some demographic factors, educational qualification, level of confidence in teaching children with special needs, training and teaching experience had significant influence on teachers' attitude towards inclusive education. Results indicate a significant difference in the two groups with regard to their training needs. Analysis reveal that teachers of both the sections were facing various problems in implementing inclusion and were in favour of partial inclusion rather than full inclusion. Findings indicate the need of more in-service teacher training and increased availability of resources for the teachers to successfully teach in inclusive settings in India