One consequence of successfully breeding dairy cattle for increased production has been the well-documented decline in their health and fertility. Broadening dairy cow genetic selection goals to incorporate fitness traits has reversed the direction of this trend for fertility. However, high-producing dairy cows remain more susceptible to diseases. Genetic selection for improved health can deliver cumulative, permanent and widespread benefits that complement other efforts to reduce disease incidence. Susceptibility to all important diseases affecting dairy cattle is heritable and therefore genetic selection for improved health is feasible if appropriate phenotypic data is available for genetic evaluations.