Genotoxicity of furfuryl alcohol and 2-furyl methyl ketone is evaluated by sister chromatid exchange analysis (SCEs) in mouse bone marrow system using standard technique. Three doses of the compounds ranging from 1000-4000 ppm were given by oral gauvage to experimental animals for one day in single dose series and for five consecutive days in multiple dose series to simulate a human situation. 5-Bromodeoxyuridine (5-Brdu) was intraperitoneally injected at hourly intervals for 6 hr at a concentration of 0.04mg/g body weight. In both single and multiple dose series the animals were exposed to 5-Brdu for 26 hr and were sacrificed after 12, 24 and 48 hr following last feeding. Control animals received distilled water and same concentration of Brdu. Bone marrow slides were prepared and stained as per standard procedure. 100 metaphase spreads in second mitotic division were scored from each dose and period and subjected to statistical analysis. There was significant induction of SCEs in both single and multiple dose series with both the compounds. It was found to be dose dependant and the period dependancy showed a decline after 24 hr.