In pain management of advanced ill patients, various factors appear to be of significance: multidimensional approach and realisation of pain as a complex perception (Total Pain). Existential fear and an exceptional role of pain as a leading symptom in palliative patients ought to be mentioned—chronification of pain progresses rapidly, oftentimes with less preconditions. In advanced ill patients, even the slightest pain stimulus may result in a sensation of total pain. We discuss mechanisms-centred pain therapy (opioid therapy in particular), depending on the pain character—nociceptive, inflammatory, neuropathic, dysfunctional, mixed pain—as a challenge in palliative care: -contemporary understanding of the significance and role of WHO pain management—genetically determined polymorphism of (opioid) receptors and enzyme systems—problems of plasma protein binding and interactions of analgetic drugs—differences in the elimination of various opioid drugs—active metabolites of opioids, peculiarities of the onset, duration and regulation of action—asymmetric pain distribution, breakthrough pain, end-of-dose failure, opioid-induced hyperalgesia—practical considerations on preferred choice of analgetics in patients with different comorbidities and of advanced age.