In response to the low passing rate of its students with disabilities, administrators at a small urban elementary school in south Texas implemented coteaching. Guided by Nonaka and Takeuchi's collaborative learning framework, this qualitative instrumental case study was conducted to investigate the effectiveness of collaborative teaching in the elementary education setting. Data collection consisted of a group interview and classroom observations with a purposeful sample of 4 general education teachers and 2 special education teachers of Grades 3-5 math and language arts who were coteaching at the time of the study. Teachers' perceptions regarding the effects of their professional relationship on collaboration efforts and of the effectiveness of coteaching in meeting the needs of students with disabilities were examined. Emergent themes were identified from the data through open coding and verified through NVivo and a peer reviewer. The findings showed that participants perceived coteaching to be an effective teaching strategy for working with students with disabilities. They suggested the following areas for improvement in their school's current coteaching program: parity among teachers, administrative support, shared planning time, relevancy of training, collaboration, and follow through regarding the roles and responsibilities of teachers. Based on the results, a professional development workshop was developed to improve the overall effectiveness of the coteaching program and better meet the needs of students with various disabilities in general education classrooms. The provision of training through the workshop may positively affect teachers' perceptions and implementation of coteaching. An improved academic environment in cotaught classrooms may benefit students with disabilities. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]