Although the life expectancy of men is commonly less than that of women, previous analyses of a longitudinal data set revealed a sub-sample of older men whose survival curves over twenty years are similar to those of the women in the sample. The main purpose of this research is to identify factors which differentiate this group of "successful" males from the other males in the sample. Data from the two groups of males (and two groups of females) were examined using analysis of variance, chi 2 analysis, and survival analysis. Data include measures in a variety of biomedical, functional, behavioral, and psychological areas collected during in-home and hospital examinations. Results show that "successful" males have significantly higher scores in both cognitive abilities and health, initially and at longitudinal follow-ups. The combination of overall high scores in the multiple domains evidently gives this group of men an advantage over the others. The results emphasize the importance of recognizing the sub-groups in the aging population with different developmental patterns, and tailoring both research and services to the uniqueness of these groups.