Serum malondialdehyde (MDA), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and histological analysis of lungs were carried out in twenty rats exposed to smoke from transfluthrin impregnated insecticide paper. The rats were divided into five groups (I, II, III, IV and V) of four each. Group one served as control while Group II, III, IV and V were exposed to smoke from transfluthrin impregnated paper Insecticide for 15, 30, 60, 120 minutes daily for four weeks respectively. On the 29th day, the rats were euthanized and blood sample was collected and centrifuged for analysis of biochemical parameters (MDA, AST, ALT and ALP), the animals were dissected and lung tissues were collected for histological analysis. Significant increase (p<0.05) in all parameters (MDA, AST, ALT and ALP) were observed in a time dependent pattern compared to normal control. However, histopathological analysis of the lung tissues shows no pathological changes between test groups and normal control. Thus, exposure of rat to smoke from transfluthrin impregnated paper insecticide modifies biochemical parameters (MDA, AST, ALT and ALP) but within the context of duration of this research, no significant pathology was observed in lung tissues. Transfluthrin impregnated paper insecticide should be used with caution.