Beyond cognitive outcomes, inquiry instruction can have positive general and differentiated affective outcomes. In this exploratory study, teacher-nominated high- to low-average achievers in Grades 5 through 9 (N = 272, mean age 11.7 years), in classrooms exhibiting rare, occasional, and frequent inquiry qualities, were assessed on Csikszentmihalyi's construct of flow, following a recent unit and reflecting on their favorite subject. We focused on flow because it addresses education and life in general, and flow and inquiry invoke challenge and persistence. Interviews complemented these data. High-achieving participants reported most flow in inquiry and in their favorite subjects; in both situations, they could participate in determining the content. All students reported greater flow in inquiry-based activities and environments, and in their favorite subjects versus recent units. All preferred challenging over easy work although for different reasons. All highlighted feeling able to succeed and interest in an activity to experience flow.