Aim:Two bacterial strains of Agrobacterium rhizogenes, A13 and 9534 were evaluated for induction of transformed hairy roots in Linum mucronatum ssp. mucronatum, a high value medicinal plant.Materials and Methods:The hairy roots were successfully initiated, through infecting the hypocotyl and root explants and the A13 strain performed a high transformation frequency for hairy roots induction. Transgenic status of hairy roots was confirmed by polymerase chain reaction (PCR) analysis of the rol genes. Growth kinetics of transgenic roots induced by two strains indicated a similar pattern of growth, with maximum growth occurring between 42 to 56 days. The lignan contents in hairy roots were analyzed using high-performance liquid chromatography (HPLC) method.Results:Transformed cultures showed significant differences (P < 0.05) in lignan content. The highest amount of Podophyllotoxin (PTOX, 5.78 mg/g DW) and 6-methoxy podophyllotoxin (MPTOX, 49.19 mg/g DW) was found in transformed lines induced by strain A13, which was four times higher than those of non-transformed roots. The results showed that hairy root cultures of L. mucronatum are rich sources of MPTOX.Conclusion:hairy root cultures from L. mucronatum can be used as a useful system for scale-up producing MPTOX and precursors for the production of antitumor agents in substitution with PTOX by considering the appropriate optimizations in future studies.