This PhD dissertation is a contribution to discussions about personal responsibility in relation to distributive justice in health and health care. It is a contribution to contemporary political philosophy in general, but in particular to luck egalitarian theory. I aim to answer three focal questions: 1) What role ought personal responsibility to play in distributive justice in health and health care? 2) What does it take for an individual to be responsible for her own health condition (or responsible in general)? And 3) what is the relation between responsibility and cost-responsibility? It consists in four articles, but I also offer, first, an introduction, second, a section on different efficiency-based political reasons to hold individuals cost-responsible for behaviours that leads to increased risks of diseases, and third, a section on the methodology I use. In my first article I bring recent political philosophical discussions of responsibility in egalitarian and luck egalitarian theory to bear on issues of social inequality in health, and access to health care. I argue that distributive justice in health and health care should be sensitive to responsibility, but also that individuals at the most fundamental level never are responsible in such a way that appeals to individuals’ own responsibility can justify inequality. This explains why we should give free and equal health care access – also to individuals affected by diseases for which lifestyle choices are a risk factor. It also explains why we have justice-based reasons to reduce social inequality in health. In my second article I investigate and (partly) object to a suggestion put forward by Shlomi Segall, according to which we should exchange the notion of responsibility with a notion of Reasonable Avoidability in the luck egalitarian theory. I argue that the size of the health-care costs related to smoking and obesity is relevant for whether society reasonably can expect individuals to avoid smoking and obesity. In my third article I ask what it fundamentally takes for an individual to be responsible for overweight or obesity. I examine what (in philosophy) appear to be the three basic approaches to responsibility. To illustrate the implications of each of them I introduce a made-up obese test person, who eats too many high fat cakes, and I show what it takes, according to each of these theories, for her to be responsible for her obesity. I show that only one of these approaches can justify the widespread intuition that much causal influence on obesity, such as genetics and social circumstances, diminishes, or completely undermines, personal responsibility. This approach, however, most likely implies that personal responsibility is generally impossible. I argue, nonetheless, that this approach is plausible. In my fourth and final article I proceed under the assumption that responsibility is possible. I examine the relation between responsibility (for one’s own health condition) and cost-responsibility (for health care expenses). This involves a discussion of what it plausibly means to burden the health care system, since, as I argue, if there is no burden then there is no justice-based reason for cost-responsibility, even if there is responsibility. I argue that we should understand the burden by comparing actual responsibility-tracking costs and counter-factual (nearest possible world) non-responsibility-tracking costs