In Libya the plants Myrtus communis and Plantago albicans are commonly used in folk medicine to treat various diseases. However, there are a large number of plant compounds which can cause many aberrations in genetic material. This study was carried out to investigate any possible cytotoxic and mutagenic effects for M. communis and P. albicans on mitotic criteria of cell cycle and chromosomes. Two infusion concentrations were prepared for each plant, one of them was used as folk medicine (o.25 mg/ml) and other as to 10 times of this value (2.5 mg/mL). Bean (Vicia faba, L.) root-tip cells (RTC) and Balb / C mice (Mus musculus) bone-marrow cells (BMC) were used as test systems. The M. communis infusions at both concentrations and the P. albicans infusion at the lower concentration had no statistically significant depressive effect on mitotic criteria of RTC. Where as significant depressive effect on these criteria of RTC was found for the high concentration of P. albicans as compared with a negative control. No significant effect on the induction of chromosome aberrations and the rate of mitotic index of BMC was found by using infusions of P. albicans and M. communis as compared with control.