BACKGROUND: The possible consequences of the long intermittent fasting schedule during Ramadan (one month of food and water intake limited to night hours, a practice that is followed by the majority of the Muslims worldwide) on certain biochemical constituents or coagulation variables have not been extensively documented. PATIENTS AND METHODS: During the month of Ramadan and two months after, we monitored the concentration of different plasma lipoproteins, lipoprotein (a) [Lp(a)], apoproteins A(1) and B, fibrinogen, factor VII activity and some selected hematological factors in 50 healthy subjects who were employees of institutes related to the Isfahan University of Medical Sciences and aged between 30 and 45 years. The effect of fasting in Ramadan on the relationship between biochemical and coagulation variables was also investigated. RESULTS: The values of apoprotein B, Lp(a) and low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio were significantly decreased during Ramadan (P<0.05), while total cholesterol (Tot-C), triglycerides (TG), LDL-C, HDL-C and fasting blood glucose did not change during that month. Among coagulation and hematological factors, fibrinogen level and factor VII activity were significantly decreased during the month (P<0.05). Results also indicated a significant positive association between fibrinogen level and Lp(a), factor VII activity and Tot-C, LDL-C, TG and Apo B during Ramadan. CONCLUSION: Our findings contribute to a better understanding of previous reports, as the metabolic and coagulation changes that are considered as atherosclerosis risk factors are counterbalanced during Ramadan.