1. Seizure threshold is an important variable in modern ECT treatment planning. To date, age, gender, and electrode placement have been used to predict seizure threshold, but the potential impact of ethnicity has received little attention. 2. In a retrospective pilot study of patients who received ECT, 20 pairs of first admission, right unilateral-treated, age- and sex-matched black and white patients were compared. 3. Black patients had higher seizure thresholds and were more likely to require restimulation, despite the finding that they were more likely to have been receiving concomitant medications which lower seizure threshold. However, ethnicity was confounded with variations in ECT dose titration, which were the strongest predictor of seizure threshold. 4. There were no differences in seizure length. Further study is necessary to confirm the impact of ethnicity on seizure threshold.