Examination stress is a basic factor that may affects many organ and systems of the body. There is a relation between stress and biochemical and physiological markers. This study examined the level of oxidative stress markers and cortisol levels in medical students during and after examinations. Cross-sectional study was conducted at the College of Medicine Chukwuemeka Odumegwu University, Uli.  Forty (40) healthy medical students planning to take their professional exam were recruited. Students with health problems that may alter immune oxidative stress measures were excluded from the study. Three samples were taken each from the students at 6-months and 2 days prior to the examination, and third sample collected two week after the examination.  Eight milliliters (8 ml) of blood samples were collected from all subjects by sterile disposable. The analysis of oxidative stress markers (superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA) and total antioxidant status (TAS)) were determined by standard colorimetric method, while analysis of cortisol was done using enzyme-linked immunosorbent assay (ELISA) technique. The mean levels of MDA and cortisol were significantly higher in 2 days pre exam condition than 6 months pre and one week post exam conditions, also the activities of SOD, GPx and TAS were significantly lower in 2 days pre examination conditions, but the difference between the 6 months pre examination state and two weeks post exams state was non-significant except in the cortisol level. Examination in medical school are stressful enough to produce changes in the levels of antioxidants and cortisol level. Though the changes has a transient effect on deranging the biochemical marker.