The principal models of the physician-patient relationship are analysed in terms of their historical development. An outline is given of the clinical, psychological and ethical particularities of the approach to patients with amyotrophic lateral sclerosis. The peculiarities of this disease are so exclusive that they do not resemble other progressive diseases with a negative prognosis, and therefore require an equally exclusive approach to the physician-patient relationship. This approach should not only be informative, scientific and interpretative-deliberative, but must simultaneously be founded on a solid therapeutic alliance aimed at seeking the best interests of the patients while respecting their autonomy as well as their "good" (not only in the sense of physical well-being, but also in terms of respect for their personal values). This is the only way to confront the conflicts that inevitably arise (especially in advanced stages of the disease) without the risks associated with a desire to escape or to adopt extreme solutions (such as euthanasia and therapeutic insistence) and without the risk of burn-out.