Abstract: Sawdusts are major by-product of wood processing with diverse uses. Extracts of sawdust of different wood type differ due to the different chemical composition inherent in them. The aim of this work was to utilize micronuclei test as a standard system to monitor toxicity using C. gariepinus as a bioindicator. For this, the fish were exposed for 21 days to extracts of five species of woodshavings /sawdusts collected from Okobaba Timber depot, Lagos. Extracts of Populus euphratrica oliver, N. dendiirichi, Eucalyptus botryoides, Acacia seberiana, Raphia hookeri mann were used. Micronucleus genotoxic studies were carried out at graded concentrations of the extracts. Genotoxic procedure was done through collection of blood from the peripheral caudal fin.