The role of dietitians is to counsel patients on special dietary modifications, develop dietary plans and provide dietary advice for healthy lifestyle in order to promote health and prevent disease. As lifestyle changes have become a primary reason for the increasing prevalence of non-communicable diseases in recent decades, it appears that nutritional therapy should play an important role in the multidisciplinary healthcare system. The aim of the review was to evaluate the role of nutritional support provided by dietitians in the prevention and treatment of chronic diseases in terms of its clinical and cost-effectiveness, according to their range of activity and qualifications. The evaluation was based on the review of the current literature. The costs of the treatment of non-communicable diseases encompass the costs of the treatment of the disease itself, costs of its complications and costs resulting from the decline of the productivity of patients. The results of studies indicate that nutritional support provides not only clinical but also cost benefits in the prevention and treatment of various non-communicable diseases. Every €1 spend on dietary counseling of patients with obesity or obesity-related diseases approximately returns a net €14 to €63 over a period of five years. Dietitians appear to be more effective in counseling overweight or obese patients with present risk factors compared to other specialists, however the barriers to accessing a qualified dietitian and problems with the reimbursement for services still exist. As adequate professional qualifications of dietitians appear to be an important factor determining the effectiveness of implemented dietary care, an additional training courses for dietitians and enhanced cooperation of hospitals and medical universities are needed.