As 4/4 block scheduling was implemented in North Carolina, many public schools offered staff development to help teachers make the transition from a six- or seven- period school schedule, but little is known about the staff development provided. The purposes of this study were to determine the Stages of Concern of North Carolina public school teachers related to 4/4 block scheduling, their perceived professional development needs, and the relationships among their Stages of Concern, professional development needs, and selected characteristics. By calling each school district's central office, the researcher determined that 248 North Carolina high schools had implemented 4/4 block scheduling as of fall 1998. A list was developed of 73 schools that implemented block scheduling in the fall of 1996, 1997, and 1998. From this list, five schools were randomly selected for each of the three years, resulting in a sample of 15 schools. At each school, five teachers were selected from each of three teaching areas: academic, workforce development, and special subjects. Thus, of the1086 teachers employed at the 15 participating schools, 225 teachers were included in the sample. The questionnaire for this study contained three parts: (a) the Hall and Loucks (1979) Stages of Concern questionnaire, (b) a professional development needs section, and (c) a teacher characteristics section. Results of the study indicated that the teachers were concerned about the success of students in the classroom and the impact of 4/4 block scheduling on their students. Consequence was the peak Stage of Concern for the largest percentage of responders, and collaboration was the peak for the second-largest percentage. Teachers with less experience had higher informational concerns than their peers with more teaching experience. On four of the nine professional development needs, more recent adopters of 4/4 block scheduling indicated significantly less need for professional development than those whose schools adopted this schedule in previous years. Thus, as teachers became more experienced with 4/4 block scheduling, they may have had problems that were unforeseen when this schedule was initially adopted. Implications for practice and further research based on the results of the study were suggested.