Bispecific aptamers having a first end that specifically binds to a first tumor specific marker, tumor antigen, or viral protein and a second end that specifically binds to a second tumor specific marker, tumor antigen, or viral protein are provide. The bispecific aptamers can be used to treat cancer or virally infected cells. Generally, the bispecific aptamers bind to two surface proteins, preferably different proteins, on the same cell. In a preferred embodiment the bispecific aptamers bind to two different tumor markers, tumor antigens, tumor specific proteins and combinations thereof.
