The aim of this prospective, randomised, double–blind study was to evaluate the efficacy of intramuscular (IM) tramadol 100 mg in emergency department treatment of acute migraine attack and to compare it with that of IM diclofenac sodium 75 mg. Forty patients who were admitted to our emergency department with acute migraine attack according to the International Headache Society criteria were included in the study. Patients were randomised to receive either tramadol 100 mg (n=20) or diclofenac sodium 75 mg (n=20) intramuscularly. Patients rated their pain on a four–point verbal scale (0=none, 1=mild, 2=moderate, 3=severe) at the beginning of the trial and at 30, 60, 90 and 120 min. At each time interval, severity of associated symptoms were also questioned and recorded. Global evaluation of the drugs by patients and doctors were also recorded. Patients were also asked if they would prefer the same injection in future visits. Any adverse events, whether related to the drug or not, were also recorded. Patients were followed up by telephone 48 h later to check for any headache recurrence. Two–hour pain response rate, which was the primary endpoint, was 80% for both tramadol and diclofenac groups. There were no statistically significant differences among groups in terms of 48–h pain response, rescue treatment, associated symptoms’ response, headache recurrence and adverse event rates. Fifteen (75%) patients in the tramadol group and 16 (80%) patients in the diclofenac group stated that they may prefer the same agent for future admissions. In selected patients, tramadol 100 mg IM may be an effective and reliable alternative treatment choice in acute migraine attacks.