Anticancer drugs have been shown to have antiviral abilities as well. The two types of diseases are similar in that they hold the cell in a continued growth phase. Therefore, if a drug has anticancer activity, it could have antiviral activity as well. I was interested in drugs that could inhibit DNA replication, since both cancer cells and cells infected with a DNA virus have increased DNA replication. Organotins are known to have anticancer activity and are thought to inhibit DNA replication. In this study, four cancer cell lines (from the NCI 60) and two DNA viruses, HSV-1 and vaccinia, were used to study the anticancer and antiviral activity of several series of organotin polymers. The cancer types and HSV-1 used in this study were chosen due to their prevalence in the human population. Cancer causes 550,000 deaths a year. Also, about eighty-five percent of the population is infected with HSV-1. Vaccinia is the strain used for vaccination against the small-pox virus, which is a concern due to the threat of bioterrorism, so it was included in the study as well. Several concentrations were used to determine the amount of polymeric drug that inhibits growth of the cancer and normal cell lines by fifty percent. The concentration of the polymeric drugs that inhibited fifty percent of the HSV-1 and vaccinia viruses was also determined. I found that the most effective sets of polymeric drugs for anticancer activity were determined to be the hydroquinone and diethylstilbestrol series. The most effective set of polymeric drugs for antiviral activity was also the hydroquinone series. My study was done to determine if the polymeric drugs would be more effective than cisplatin, a widely used anticancer drug that has platinum as its active moiety, as well as dibutyltin dichloride, an organotin monomer.