Although formaldehyde is widely used in consumer goods to protect the products from spoil age by microbial contaminations , research has shown that it ha s various side effects. Therefore t he aim of this study was to investigate the cyto genetic effects of formaldehyde solution on mice , and investigate the possible protective effect of vitamin C a gainst the cytogenetic effects of formaldehyde. Thirty - six Swiss albino mice were exposed to various concentrations of formaldehyde. The animals were divided in to six groups (two groups received 1 /10 LD 50 , 1/5 LD 50 of formaldehyde other two groups receive d vitamin C in addition to 1 /10 LD 50 , 1/5 LD 50 of formaldehyde and two control groups) . Animals were sam pled at two different times (48 and 72 hrs). The results revealed that the formaldehyde increased the number of structural and numerical chromosomal abe rrations, and decrease the rate of cell division (mitotic index) at either 48 or 72 hrs . T here is no significance difference between the two doses of formaldehyde were observed. Moreover, the use of vitamin C g ave promising results against formaldehyde tox icity as it significantly decreased the frequency of chromosomal aberrations and improving rate of cell division.