Autism spectrum disorder (ASD) is a lifelong neurodevelopmental disorder. It permeates multiple developmental areas, including social communication challenges and restricted, repetitive behaviors. The prevalence of ASD has increased during the last few years and so has the inclusion of the students with this disorder in regular primary schools. The teacher's role in inclusion of the students with ASD is informing themselves about ASD, collaborating with the rest of the stakeholders and planning and carrying out individualized lessons. The aim of the research was to question the attitudes and experiences of the primary school teachers from general primary schools about the inclusion of the students with ASD in a regular primary school. There were 152 lower and higher grade teachers of regular primary schools in the Republic of Croatia, which had an experience with students with ASD during their length of service, participating in this research. The results were collected through an online survey questionnaire throughout March and April of 2021 and were calculated and presented via descriptive statistics. According to the teachers' opinions who participated in this research, the parents/guardians of the student with ASD have the biggest role in including the students with ASD in regular primary schools while his classmates have the smallest role. The teachers think they have a major role. Most frequently, they inform themselves about ASD by examining the existant documentation of the student with ASD whereas, least frequently, by participating in professional training. The teachers most frequently identify the characteristics of the students with ASD and least frequently their strenghts. Most frequently, they collaborate with teaching assistants and least frequently with school doctors. When carrying out individualized lessons comes into question, the teachers most frequently observe the student's achievements, work and educational needs whereas, least frequently they place the students further from the object which might deconcentrate them, adapt the classroom conditions to their needs and adapt the sitting schedule in the classroom to them.