The relations of diet adherence (DA) and self-monitoring of blood glucose (SMBG) to metabolic control, as measured with glycosylated hemoglobin A(1c) (GHbA(1c)), and correlates of self-care were examined among a type I diabetic sample (n = 423). The Health Belief Model (HEM), supplemented by other factors (locus of control, self-efficacy, health value, and social support), was used as a theoretical model. In multiple regression analyses both DA (p<.01) and SMBG (p<.001) were related to GHbA(1c). Theoretically derived path models for HEM (estimated by LISREL) required modifications. DA showed strong associations with diabetes related social support (p<.001) and net benefits of DA (p<.001). SMBG showed strong associations with self-efficacy in SMBG (p<.001) and net benefits of SMBG (p<.001). The revised models explained 14% and 21% of the variation in DA and SMBG, respectively. The results suggest that although perceived net benefits are important determinants of both SMBG and DA, DA is also related to diabetes support, whereas SMBG is more strongly related to perceived self-efficacy. Thus self-care regimen should be planned individually for diabetic patients.