The theory of Health Locus of Control (HLC) refers to measuring people’ beliefs about whether or not health is determined by their behaviors through the Multidimensional Scale which introduced by Wallston et al. Internality and externality (internal and the two separated external dimensions of locus of control of “Powerful Others” and Chance) have been used as a predictor of various health behaviors in a large number of studies with a positive correlation, such as physical activity, medical teeth protection, diet, patients-doctors communication, medication adherence. Nevertheless, the Achilles' heel of HLC is due to weaknesses of the research tool itself (with the continual development of new subscales and the independence of its three dimensions), as well as the significant interactions of other psychosocial determinants, for instance age, gender, value of life, ethnicity, religiosity and social cohesion. In consequence, it is imperative to add and include components of other theoretical models (self-efficacy, the Theory of Planned Behavior etc.), which have been found to handle and clarify better other views and aspects of human behavior.