The endocannabinoid system (ECS) controls a large number of vital functions. Suboptimal tone of the ECS in certain regions of the nervous system may be associated with disorders that are also associated with pain. Pain and inflammation processes can be modulated by the exogenous supply of cannabinoids. Low-to-moderate pain-relieving effects and in individual cases large pain-relieving effects were observed in randomized, controlled studies of various types of chronic pain. People with chronic neuropathic pain and stress symptoms seem to particularly benefit. The therapeutic range of cannabinoids is small; often small doses are sufficient for clinically significant effects. The “Cannabis-als-Medizin-Gesetz” (cannabis as medicine law) allows the prescription of cannabis preparations under certain conditions. Available data indicate good long-term efficacy and tolerability. However, there is little systematic long-term experience from clinical studies.