The National program for chronic disease started in Tunisia in 1993. It aimed to unsure an effective and standardized management of these chronic diseases, in primary heath care centers, based on standardized guidelines and structured medical records. Aim: To assess the data completeness of the structured medical records of hypertension and diabetes patients in primary health care centers of the governorate of Nabeul (Tunisia) Methodology: Our evaluative study enrolled medical records of chronic disease patients, followed for at least one year in the primary care centers of the governorate of Nabeul. The data of the 10 items regarding the first medical visit were assessed: patient identification, disease classification; personnel medical history, family medical history, disease history, signs and symptoms, initial physical examination, Cardiovascular risk evaluation, dietary and nutritional behavior, and the final medical Conclusions: The completeness of data was measured considering if a patients’ record contains all desired types of data in the different items. In each primary health care center, 15 records have been assessed. Results: In total, 23 primary health care centers have been enrolled and 345 medical records have been assessed. Data for patient’s identification (name, surname, gender) was available in 92. 2%of medical records. Availability of data for disease classification was 81.8 %, personnel medical history 66.5%; Family medical history 63.3%, Signs and symptoms 41.3%, Initial Physical examination 52.6%. Data regarding Cardio-vascular risk evaluation and the Conclusions: of the initial medical visit were missing respectively for 78.4% and 63% of medical records. Conclusions: We found that the completeness of data in medical records was not satisfying. Assessment of the data quality is important not only for the patients but also for researchers and policymakers. Thus, sensibilization, medical record simplification and an evaluation of the national program is important at this step.