Opioid analgesics differ in terms of their potency and the way they impact opioid receptors. The choice of a drug should also depend on its non-opioid effects, which give them their special properties. However, it is the patient that is the most important factor of variability; the type of pain and the patient’s clinical situation are the aspects that should be taken into account when starting the treatment. Patients with impaired renal function require special attention. Opioid analgesics in chronic kidney disease should be adjusted to the degree of renal impairment, which will determine choices at the initial stage of the treatment and during its continuation. In the case of hydrophilic drugs or drugs with active metabolites, their dose should be adjusted to the degree of renal failure, the course of treatment should be monitored, and drug doses — both in background and breakthrough pain — should be modified, if necessary. In this group of patients, lipophilic opioid analgesics such as buprenorphine, fentanyl and methadone may be the right choice. In the case of insufficient analgesia, the same rules of titration apply to determine the optimal dose as in patients with normal renal function.