Accumulated knowledge of women's health remains incomplete, and its fragmentary nature may be explained by a variety of factors: the contrived 'invisibility' of women in research, normative male predominance, gender bias, an inadequate female power base, insufficient resources, etc. The health paradox--i.e., the relative longevity of women versus their greater proneness to disease and symptoms--is discussed and two models, a biological/genetic and a sociocultural model, are presented in an attempt to explain it. The adoption of a gender perspective in future research is suggested as a possible mean of eliciting new knowledge in this field.