Increased platelet aggregation as well as changes in coagulation factors have an important effect on the occurrence of atherogenicity and cardiovascular diseases. Fasting in general has been used in medicine for medical purposes when other measures fail. Since Ramadan fasting is different from total fasting, the present work was conducted to study the effect of Ramadan fasting on lipid pattern, some blood coagulation parameters, blood pressure and body mass index (BMI)--as atherosclerotic risk factors--in one hundred and three apparently healthy obese volunteers (15 men and 88 women) aged 15-52 years. The study comprised an initial visit for assessment V1 (before Ramadan) and three other follow up visits: V2 (at the end of Ramadan), V3 (4 weeks after Ramadan) and V4 (8 weeks after Ramadan), Targets were subjected to an interview questionnaire, complete physical and clinical examination, anthropometric measurements, dietary profile, and laboratory assay of complete blood picture (CBC), fasting serum glucose level (FSG), serum lipid pattern: total cholesterol (TC), triglycerides (TG), high density lipoproteins (HDL-c) and low density lipoprotein (LDL-c), lipoprotein a Lp (a), apolipoprotein A1 (APA), and apolipoprotein B (APB) levels; bleeding (BT) and clotting time (CT), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen and plasma factor VII activity. Statistical analysis was performed using Chi squared, Fisher exact, Student t test, paired t test and Pearson's correlation coefficient. Statistical significance was defined at P < 0.05. The study showed that by the end of Ramadan fasting, there was a significant improvement in the mean levels of hemoglobin (Hb), TC, TG, HDL-c, LDL-c, TC/HDL, LDL/HDL, Lp (a), APA, APB, PT and systolic (SBP) and diastolic blood pressure (DBP) that persisted for four weeks after fasting (P < 0.05). Ramadan fasting has not adversely affected leucocytic count or coagulation parameters (P > 0.05). There was also a significant association between dietary intake, SBP, DBP, weight, BMI, percent body fat and waist, fibrinogen and factor VII activity and TC, TG, HDL-c, LDL-c, LDL/HDL, Lp (a) and APB (P < 0.05). The model of Ramadan fasting could be followed as a behavior modification program to control or prevent atherogenicity because of its positive impact on the lipid pattern, blood count and coagulation parameters.