Objective: The purpose this research was to investigate the effectiveness of inclusive in-service training on the regular primary teacher’s attitude toward inclusive education of students with hearing impairment. Methods: The method of this research was quasi-experimental, including 50 sample people (25 experimental, 25 control group). They were selected randomly without replacement. During the study, the experimental group was exposed to the inclusive in-service training and control group did not any service. Results: Covariance analysis showed that experimental group’s attitude became more positive towards control group (P<0/01). Furthermore, the analysis of results manifested that experimental group’s attitude became more positive at domains of philosophy of inclusive education, feeling of competence, security supports, relationship of normal and students with hearing impairment, and expected outcome of inclusive education, but did not show any significant difference in classroom learning climate (P>0/05). Conclusion: Holding inclusive in-service training can change some related attitudinal aspects.