Statistical analysis of rubella titers (values partly from the literature) reveals that about 4% of those between 16 and 30 years of age are without antibodies. Older age groups show complete immunization of all individuals. Mean rubella titers in subjects between 16 and 40 years of age are identical. A group of elderly subjects (60 years) shows decreased titers that could be statistically verified. IgG serum concentrations in individuals over 60 years are significantly elevated if compared with normal medium values. The results are discussed in view of previous studies about antibodies and IgG concentration in the aged.