Tongue angioedema is a well-recognized side effect of angiotensin-converting enzyme inhibitor particularly during the first few months of initiation. Unilateral tongue involvement is rarely encountered. We report the case of a 78-year-old woman who presented with unilateral right side tongue angioedema, which occurred after two years of lisinopril use. She did not have any respiratory distress and her symptoms had completely resolved after twelve hours of observation. Lisinopril was discontinued and no recurrence of angioedema was reported.