The effect of chronic consumption of fresh and thermally oxidized palm oil on faecal composition and moisture of rats was studied. The animals were divided into 3 groups of five rats each. The first group control was fed on normal rat chow only. The second (FPO) and third group (TPO) were fed diet containing either fresh or thermoxidized palm oil (15% wt/wt) for 14 weeks. The rats in the entire group were allowed free access to food and water. At the end of the feeding period, faecal protein, glucose, moisture and electrolyte were determined. The results show that there was no significant difference in faecal weight among the groups. The faecal protein in control, FPO and TPO was 27.50±33.42g/100ml, 31.50±3.67 and 51.68±0.005g/100ml respectively. The faecal protein in TPO was significantly higher (P<0.05) than that in control or FPO group. Faecal glucose was significantly lower (P<0.05) in TPO than control or FPO. There was however no significant difference in faecal Na+ and K among the groups. The total moisture loss and total faecal lipids were significantly raised (P<0.05) in TPO than in control or FPO group. In conclusion, chronic consumption of thermally oxidized oil may lead to loss of proteins, lipids and water in faeces. This may be dangerous to health and so thermally oxidized oil should be used with caution.