 This study is designed to determine the safety of IL-12 gene therapy for patients with recurrence of prostate cancer after radiation therapy and those with or without metastatic disease with a prostate gland intact. These, of course, would include recurrent prostate cancer after definitive radiation therapy. The prostate cancer will be treated with a prostatic injection of a replication-defective adenovirus vector delivering the IL-12 gene. Following virus injection, patients will be hospitalized for 23 hours for observation. Only one course of therapy will be administered. Each patient will be carefully monitored for toxic effects. Three to five patients will be tested with a low dose of virus and if there are no serious adverse side effects, the dose will be slowly escalated in subsequent groups of 3-5 patients or until unacceptable toxicity is reached. Effectiveness will be monitored by serum prostate-specific antigen PSA, transrectal ultrasound of the prostate, prostate biopsy and comparison of survival times to historical survival times for patients with radiation recurrent prostate tumors. The primary objective of this initial study is to determine whether the treatment is associated with significant toxicity. 