In this study social work instructor and student reactions to a behavioral instructional method called mastery learning were examined using qualitative methods. Mastery learning utilizes additional learning time and repeated testing opportunities to increase student learning. Students rated how helpful seven instructional elements of mastery learning were and described what they liked and disliked about the instructional elements. Students (N=342) rated the mastery elements as either very or quite helpful 93% of the time. For instructional elements, comments ranged from a high of 94% positive (ungraded quizzes) to a low of 82% positive (make-up exam, outside class reviews). The mastery instructor reported increased classroom time efficiency; increased focus on essential material; and a stronger coordination between teaching and testing. (Contains 45 references.) (JDM)