Statement of problem: The electric pulp test (EPT) is an important diagnostic aid in evaluation of pulpal vitality. It was postulated that premedication with analgesics can decrease tooth sensitivity to electric stimulation   Purpose: The purpose of this study was to evaluate the effect of premeditation with ibuprofen on the responses of vital central teeth to electric pulp tester.Materials and method: This clinical trial study was performed on 88 intact maxillary central and lateral incisors. After taking medical and dental histories and clinical examinations, electric pulp testing was done using tooth paste as conducting medium and the results were recorded. Afterwards, each subject received a 400mg ibuprofen tablet and one hour later, electric pulp testing was conducted again. The data were statistically analyzed using t-test to compare pre- and post-medication records.Results: The mean EPT scale of teeth before ibuprofen administration was 2.5, whereas after drug administration the mean EPT scale of the teeth was 2.7. Statistical analysis showed significant differences.Conclusion: This investigation showed that, although ibuprofen decreased the tooth sensitivity to electrical stimulation, but with proper attention in using pulp tester, it could still be a valuable aid in clinical practice for patient’s receiving Ibuprofen.Key words: Electric pulp tester, Ibuprofen, Maxillary incisors