The objective of this study was to evaluate the severity of acute pain and side effects in breast cancer patients postoperatively treated with two regimens of tramadol with paracetamol in a prospective double-blind study. Altogether 117 breast cancer patients who had axillary lymphadenectomy were randomized into two analgesic study groups and the analgesic treatment lasted 4 weeks. Stronger analgesia group received every 8 h 75/650 mg of tramadol with paracetamol, while weaker analgesia group received every 8 h 37.5/325 mg of tramadol with paracetamol. Patients with the higher dose of tramadol had less pain during the 1st and 4th week than patients with the lower dose. Frequency of nausea, vomiting, lymphedema or range of shoulder movement was not significantly different between the two groups of patients. Constipation was significantly more common in the group with stronger analgesia during the 2nd week in comparison to patients with weaker analgesia. The patients who were on 75/650 mg of tramadol with paracetamol had less pain in comparison to patients who were on 37.5/325 mg. Side effects were mild, but common in both groups of patients.