We studied the long-term follow up of abnormal T wave morphology (notched, low amplitude, and inverted T waves) of five female patients with LQT2 (HERG) mutations. The patients, aged 43, 19, 27, 26, and 56 years, had experienced syncopal attacks and were followed up for 3-17 years (average 9.4 years). Patients were treated with a beta-blocker alone (2) or combined with other drugs (3). The mutation in four patients was missense (A614V, T613, E130K) and its location was the pore region (3) or between the S1 transmembrane region and N-terminal (one). The fifth patient had an intragenic deletion (49 bp deletion) at HERG exon 4 (S1 transmembrane region and N-terminal), which was not identified as having any mutation. The patients manifested a notched T wave in at least one left precordial or limb lead (I, II or aVF). A low T wave amplitude was shown in at least one lead, and deeply inverted or biphasic waves in right precordial leads were also associated with these findings. The abnormal T wave finding in any of the 12 leads in our 5 LQT2 patients was shown to be widespread and was always found during the long-term follow up. The present cases suggest that notched T waves are useful for diagnosing female symptomatic LQT2 patients.