One hundred fifteen patients participated, 59 receive CA and 56 T. In the group of patients that receive CA, 58% achieved pain relief with the initial dose of 150 mg/d and 8% responded to the double dose; 34% didn’t experience pain relief. In the group patients treated with T pain relief occurred in 62% of patients with the initial dose of 200mg/d and 11% with the double dose; 27% didn’t experienced pain relief. Dif-ferences between both groups were not significant in the analgesic efficacy. The tramadol group experienced in a significant way a higher incidence of adverse events of mild intensity: nausea (p: 0.05, RR: 0.62; IC95%: 0.38-1.01), dizziness (p: 0.04; RR: 0.58; IC95%: 0.33-1.01) and lost of appetite (p: 0.001; RR: 0.08; IC95%: 0.01-0.59). Conclusion Efficacy of C and T during a treatment of 23 days was similar, no statistical differences were found. There were no dif-ferences in the analgesic effectiveness between CA and T in the management of cancer pain. With the use of T a higher incidence of adverse events of mild intensity were reported.