Introduction. Even in the last century cannabis was used in the treatment of chronic pain. The main active component of cannabis Delta-9-Tetrahydrocannabinol (THC) has been increasingly used in the treatment of nausea, vomiting, loss of appetite and depression. It is also recommended in the treatment of chronic pain. We present our first experiences with THC in the treatment of patients with chronic pain. Methods. All patients treated with THC in the period from February 1998 until January 2000 were evaluated. Pain relief and side effects of THC were examined retrospectively. Results. In the period of investigation 6 patients had been treated with THC because of chronic pain. Dosages between 5 and 20 mg/d had been used. A sufficient pain relief had been achieved in three patients. The other three suffered from intolerable side effects such as nausea, dizziness and sedation without a reduction of pain intensity. In these cases the treatment was continued with other analgesics. Conclusion. This retrospective evaluation of 6 case reports of patients treated with THC showed large individual differences in the effectiveness of THC in pain management. Prospective studies are necessary to evaluate the importance THC in the treatment of chronic pain.