The aim of this study is to determine the needs of special education teachers about curriculum development, and to implement the constructivist approach to in-service training programme for special education teachers. Furthermore, this study seeks to evaluate the developed in-service training programme. The descriptive and experimental methods were applied in this study. The sample consists of 84 special education teachers that have completed the needs analyses questionnaires that has provided the basis for the development of the in-service training programme. An experimental design has been used in the second stage of the study. The experimental group of the study consists of 31 special education teachers. The implementation of the in-service training programme has taken 36 hours over a 6 months period. According to the results of the study, special education teachers need a higher level of training for curriculum development. Also, there is a significant difference between the pre-test and post-test scores of the achievement test. Moreover, teachers have declared that the programme is beneficial and also that their knowledge levels about curriculum development have increased.