Living to a late age without suffering any major health problems is a genetically influenced trait. To identify the genes contributing to this important phenotype, a 10 cM genome screen was performed in 95 pairs of male fraternal twins concordant for healthy aging. Individuals meeting these criteria were defined as those attaining the age of 70 free of cardiovascular disease (coronary surgery, diabetes, heart attack, and stroke) and prostate cancer. Six chromosomal regions were identified with logarithm of odds (LOD) scores greater than 1.2 (p<.01). A region on chromosome 4 at marker D4S1564 produced a LOD score of 1.67; this was the same marker previously linked to extreme longevity segregating as an autosomal dominant trait in centenarian families. Our results provide independent evidence that a locus on the long arm of chromosome 4 is associated with better physical aging and/or longevity.