Achievement in French and English language skills and in mathematics is compared among groups of immersion students in Grades 3, 6, and 9 in the province of Manitoba. Comparisons are also made between these groups of immersion students and a sample of students whose native language is French. Different types of programs (early and late, total and partial) offered in different settings are considered in the study. The parents, teachers, and principals of students in the study were asked to respond to questionnaires designed to provide additional information on French immersion programs in Manitoba. The study indicates that the immersion students perform as well as, or better than, the national norms in English and mathematics. French immersion programs have no negative effects on achievement in those subjects. In French language achievement and proficiency, the early total immersion program in an immersion setting produces the best results. The type of program and the setting influence French language development: students in an immersion setting and in a total immersion program obtain higher scores than those in an English setting or in a partial immersion program. (Author/AMH)