A new amphibian cell line, Bor II, is described. It was initiated from Stage 20 embryos of the discoglossid frog, Bombina orientalis. In early passages the cell line had an epithelioid morphology. Beginning at or around subcultivation 16, a more fibroblastic cell type emerged and rapidly became predominant. These later passage cells were able to proliferate in low (1.0%) serum, displayed frequent overlaps, and lacked postconfluent inhibition of cell division. The cell line was unable to survive at 37 degrees C, but grew vigorously within a temperature range of 20 degrees to 30 degrees C. The presence of two distinctive marker chromosomes in an otherwise diploid karyotype should make these cells useful for nuclear transplantation studies.