The purpose of this study was to determine if there had been a significant change in the academic achievement, as measured by Grade XII grade-point averages, of Alberta's matriculation graduates since the accreditation of Alberta high schools in 1973. The experimental population consisted of 100, 1971-72 and of 100, 1976-77 matriculation graduates who had graduated from schools in the rural school jurisdictions in Education zone 6; and of 100, 1971-72, and of 100, 1976-77 matriculation graduates who had graduated from schools in the Medicine Hat urban school jurisdiction. All of the students in the experimental population had completed their freshman year at the Medicine Hat College the year following their graduation from high school. The variables analyzed in this study were: (1) Departmental Examination Grade XII grade-point averages, (2) Teacher-assigned Grade XII grade-point averages, (3) college freshmen grade-point averages, and (4) zones (rural and urban). Correlation coefficients were calculated between Grade XII grade-point averages before and after the accreditation of Alberta high schools. Results indicated that the correlation coefficients ranged from .36 to 50. The Grade XII grade-point averages which showed the highest correlations with college freshmen grade-point averages were those which had been obtained on Departmental Examinations. The Fisher's Zr transformation statistical test indicated, at the .05 level of significance, that there was no significant difference between the zones' correlation coefficients before and after accreditation. The two way analysis of variance test results indicated that there was no significant mean difference between Departmental Examinations Grade XII grade-point averages and teacher-assigned grades. There was, however, a significant difference at the .01 level, between the rural and urban zones' matriculation graduates' Grade XII grade-point averages. The t test showed that there was no significant mean difference between the rural and urban zone's matriculation graduates' Grades XII grade-point averages before accreditation, but after accreditation there was a significant mean difference at the .01 level. The two-way analysis of variance statistical test results showed no significant mean difference in the Medicine Hat College's freshmen grade-point averages prior to or after accreditation.