Coexisting hypertension increases the morbidity and mortality associated with diabetes, and may be more so in less educated people. We analysed data from 49 904 Canadians 40-64 years of age who participated in the Canadian Community Health Survey, 2000-2001. Multiple classification analysis was used to adjust for covariates. Population weight and design effect of the survey were taken into account in the analysis. The association between hypertension and hospitalization varied according to diabetes and education. The adjusted difference in hospitalization incidence attributable to hypertension was significantly higher for the lower education group than the higher education group, and such a pattern tended to be more pronounced among diabetic people. The adjusted incidence difference attributable to hypertension was higher in the diabetic group (8.8, 95% confidence interval (CI): 4.6, 13.0%) than in the non-diabetic group (4.6, 95% CI: 3.6, 5.6%) for people with low education, but was similar for those with well-educated people. Possible reasons for the modifying effect of education on the relationship among hypertension, diabetes and hospitalization were discussed.