Fibrinogen has been detected in ME-180 human uterine cervix carcinoma cells, and synthesis of fibrinogen by ME-180 cells has been measured using [35S] L-methionine incorporation. Expression of mRNA for the B beta-chain of the fibrinogen in ME-180 cells has been identified by PCR-assisted mRNA amplification. The A alpha-, B beta-, and gamma-chains of fibrinogen synthesized by ME-180 cells were chemically and immunologically identical to those of plasma fibrinogen. These findings suggest that fibrinogen is present and synthesized in ME-180 human uterine cervix carcinoma cells, and that fibrinogen plays a role in these malignant tumor cells.