This study was conducted to identify the in-service training needs of biology teachers working in seven geographical regions, and to make content and methodology related suggestions for future activities. Research questions guiding the data collection and analysis were used to identify the teachers' in-service training needs, and beliefs and perceptions about the Ministry of Education's current in-service training courses. Differences between the in-service training needs of teachers in different geographical regions were also searched in the study. A survey questionnaire was applied in Adana, Bursa, Konya, Samsun, Gaziantep, Malatya, Kocaeli, Kayseri, Manisa, Aydin, Usak, Burdur, Karaman, Yalova, Kilis, Bayburt and Ardahan in 2005 to 338 teachers. Research results pointed at the differences between the in-service training needs and experiences of teachers working in Southeast, East and Black Sea Regions, where less inservice activities are organized, and teachers working in other regions. Therefore, the researcher suggests a school-based system where schools, national education offices and In-service Training Directorate take over the authority and responsibilities in turn.