Educational system in Croatia tries to provide an opportunity to all students to reach their full potential. Individualized Education Program is provided to students who although their difficulties can follow regular educational plan and program without changes to content, but due to their specific functioning they demand individualized teaching procedures. Furthermore, in implementing succesfully individualized programs, it is important to point out the role of the teacher who are planning and performing programs. The main aim was to investigate teacher's attitudes and knowledges about planning and implementing Individualized Education Program and to have a better view of their self assessment of their competency.Teacher's assessment of support from educational system and quality of collaboration with a mobile team of experts and with parents were investigated, too. For purposes of this research, it is developed an online questionnaire for the teacher in elementary schools from Croatia. 150 teachers participated in research. Collected data was processed in the IBM SPSS Statistics. Results show that teachers assess their knowledge as average in knowing difficulties, teaching and gradeing students with individualized programs. Teachers are displeased with knowledge which they received through formal education about teaching students with specific learning disorders, communication disorders, ADHD and support they are receiving from special educational needs coordinators in schools. It has to be noted that the greatest differences are amoung teachers considering continuing education. All things considered, theachers needs to provide more support in forms of continuing education from mobile team of experts, but also from government agency for education.