This article reports on an exploratory study of the shifts of teachers' interactions with boys from their first to their second year of using cognitively guided instruction (CGI) in their math instruction. Interaction analysis was used to analyze 22 videos, two per each of 11 teachers, who applied CGI instruction in their classrooms (a) after participating in a CGI professional development program (year 1) and (b) after practicing CGI for one year (year 2). In the eleven year 1 videos, some teachers differentiated their attention to boys and girls based on two kinds of interactions: (a) during one-to-one interactions, teachers tended to distribute their attention more to boys as compared to girls; often, that attention was unevenly distributed among boys with some boys receiving more attention than others; and (b) during whole group interactions, teachers tended to ask more boys than girls to share their strategies. In the eleven year 2 videos, some noticeable shifts occurred: (a) during one-to-one interactions, teachers tended to distribute their attention to boys and girls and among students in more balanced patterns than during the previous year; and (b) during whole group interactions, teachers tended to balance how often they called on boys and girls to share. Microanalysis of selected episodes suggests that both shifts coincided with teachers' adapting their teaching to be more aligned with CGI principles of instruction, such as attending to students' mathematical thinking processes.