This paper analyzes theoretically how a parent would optimally protect herself and her child against mortality risk that might arise from environmental and other hazards. This decision is shown to depend on the intra-family consumption pattern of risk-reducing goods and whether the unconditional risk of becoming ill (illness likelihood risk) and the conditional risk of death given that illness occurs (illness severity risk) are perfect substitutes. Implications of the theoretical model are tested using stated preference data drawn from field studies of skin cancer and leukemia risks. The test is based on a novel econometric approach to avoid the problem that people may misstate their purchase intentions for hypothetical goods when they do not actually have to pay. A key finding is that parents view illness likelihood risk and illness severity risk as perfect substitutes both for themselves and for their children. This outcome implies that: (1) parents’ willingness to pay for a reduction in mortality risk is the same whether it is caused by a reduction in illness likelihood risk or in illness severity risk and (2) when parents and their children consume the same goods to reduce risk, parents willingness to pay to protect themselves against mortality risk equates to their willingness to pay to protect their children. Results obtained may be useful in benefit-cost analyses as well as in the design of public programs aimed at hazard reduction.