Background: Adequate management of high blood pressure (HBP) and Type II Diabetes (DMII) is a challenge to the healthcare system in Chile. Aim: To evaluate the effectiveness of a case management (CM) approach to manage HBP and DMII at Primary Healthcare (PHC) level, headed by healthcare technicians with the supervision of registered nurses. Material and methods: Two primary health care centers were selected. In one the case management approach was used and the other continued with the usual care model. Patients with HBP or DMII were selected to participate in both centers. The main outcomes were changes blood pressure and glycosylated hemoglobin levels. Results: Three hundred twenty-eight patients were allocated to the intervention group and 316 to control group. At the baseline evaluation, participants at the control health center had better systolic and diastolic BP levels (SBP and DBP) , but no difference in glycosylated hemoglobin. After twelve months the adjusted mean difference in HBP patients for SBP was -0.93 (95% conficence intervals (CI) -5.49,3.63) and for DBP was 1.78 (95%CI -2.89,6.43). Among HBP+DMII patients, the mean difference for SBP was -0.51 (95% -0.52,0.49) and for DBP was -3.39 (95%CI -6.07, -0.7). No differences in glycosylated hemoglobin were observed. In a secondary analysis, the intervention group showed a statistically significant higher SBP and DBP reduction than the control group. Conclusions: The case management approach tested in this study had promissory results among patients with high blood pressure.Background: Adequate management of high blood pressure (HBP) and Type II Diabetes (DMII) is a challenge to the healthcare system in Chile. Aim: To evaluate the effectiveness of a case management (CM) approach to manage HBP and DMII at Primary Healthcare (PHC) level, headed by healthcare technicians with the supervision of registered nurses. Material and methods: Two primary health care centers were selected. In one the case management approach was used and the other continued with the usual care model. Patients with HBP or DMII were selected to participate in both centers. The main outcomes were changes blood pressure and glycosylated hemoglobin levels. Results: Three hundred twenty-eight patients were allocated to the intervention group and 316 to control group. At the baseline evaluation, participants at the control health center had better systolic and diastolic BP levels (SBP and DBP) , but no difference in glycosylated hemoglobin. After twelve months the adjusted mean difference in HBP patients for SBP was -0.93 (95% conficence intervals (CI) -5.49,3.63) and for DBP was 1.78 (95%CI -2.89,6.43). Among HBP+DMII patients, the mean difference for SBP was -0.51 (95% -0.52,0.49) and for DBP was -3.39 (95%CI -6.07, -0.7). No differences in glycosylated hemoglobin were observed. In a secondary analysis, the intervention group showed a statistically significant higher SBP and DBP reduction than the control group. Conclusions: The case management approach tested in this study had promissory results among patients with high blood pressure.