Within the Caribbean context, the island of Montserrat included, ability grouping has been employed as the major organizational strategy to address academic deficiencies among high school students. Although no sound philosophical basis for this type of class/group organization has been enunciated, recent research has shown that students with poor achievement may have acquired learning styles or strategies detrimental to their academic achievement. This paper describes a study using the Inventory of Learning Processes instrument to assess the learning styles of grade 9 students in two different ability groups (A and B) in the Montserrat high school system. The sample comprised 47 boys and 67 girls (aged 14) drawn randomly from the grade 9 population of Montserrat's two high schools. Results indicated that ability group A students performed better at deep processing, fact retention, and methodical study, compared with their counterparts in ability group B. The sex differences that emerged indicated female superiority over males on factors associated with methodical study. Findings point to a need for designing and implementing a program for improving students' learning process, especially those in the lower ability groups. (35 references) (MLH)