Placental explant culture, and cellular cytolysis and cellular differentiation have been previously studied. However, oxidative stress and nitric oxide profiles have not been evaluated in these systems. The aim of this study was to determine the release of lipid peroxidation and nitric oxide from placental explants cultured over a seven day period. Placental explants were maintained for seven days in culture and the medium was changed every 24 hours. The response was assessed in terms of syncytiotrophoblast differentiation (human chorionic gonadotropin, hCG), cellular cytolysis (lactate dehydrogenase, LDH), oxidative stress (thiobarbituric acid reactive substances, TBARS), and nitric oxide (NO). Levels of hCG increased progressively from day two to attain its highest level on days four and five after which it decreased gradually. In contrast, the levels of LDH, TBARS, and NO were elevated in the early days of placental culture when new syncytiotrophoblast from cytotrophoblast were forming and also in the last days of culture when tissue was declining. In conclusion, the levels of NO and lipid peroxidation follow a pattern similar to LDH and contrary to hCG. Future placental explant studies to evaluate oxidative stress and NO should consider the physiological changes inherent during the time of culture.