Transformed root cultures of Tagetes filifolia were established by infection with Agrobacterium rhizogenes LBA 9402. Several clones were obtained with different growth index, content of thiophenes and pattern. The isolated clones showed considerable variations in total thiophene content (27 to 11764 mu g/g fresh weight) but all had similar patterns of the different thiophenes. Only one clone excreted thiophenes (about 80% of total amount).