Aim: In most Muslim societies the daily routine and lifestyle change markedly during the month of Ramadan because of fasting during daylight hours and the altered day and night rituals. These changes could potentially have significant metabolic effects. The aim of this study was to explore the effects of Ramadan fasting and the resultant lifestyle changes on the biochemical profile and oxidative stress markers in healthy adult males. Material and Method: Forty-two healthy male volunteers following their usual Ramadan fasting routine were included in the study. The following serum variables were measured at the beginning and at the end of the month: triglycerides, total cholesterol, HDL cholesterol, non-HDL cholesterol, albumin, total protein, CRP, uric acid, ischemia-modified albumin (IMA), albumin adjusted-IMA (AAIMA), and thiol/disulfide homeostasis. Results: Triglycerides, total cholesterol, non-HDL cholesterol, NA and AAIMA levels were significantly higher on the last day of Ramadan compared to the first day (p<0.05). Fin cholesterol levels were statistically lower on the last day of Ramadan than the first day (p<0.05). However, there were no significant changes in the remaining variables (total albumin, uric acid, CRP, and thiol/disulfide homeostasis parameters). Discussion: Lifestyle, nutritional, and diurnal rhythm changes during the month of Ramadan may be associated with hormonal and biorhythm alterations which could be responsible for the observed elevations in serum IMA, AAIMA and non-HDL cholesterol levels. However, further studies are required to ascertain the direct causes of these changes.