The establishment of a new human prostatic cancer cell line is described. This cell line was derived from a poorly to moderately differentiated prostatic adenocarcinoma. It has been maintained in tissue culture for fourteen months and has been passed fifty-two times. This cell line has an ability to form colonies in soft agar suspension cultures, and also is transplantable to nude mice. Tumors grown in nude mice revealed a poorly differentiated adenocarcinoma with positive PSA staining. Acid phosphatase activity was detected in freeze-thawed cells by enzymatic assay. A karyotype analysis demonstrated aneuploidy with a model chromosomal number of 69 and six marker chromosomes.