We examined the association between residential proximity to 60 Hz high voltage (22-500 kV) overhead transmission lines (HVOTLs) and mental health (MH). The subjects were 223 mothers with a mean age of 37 years. The distance from the subject's residence to the closest HVOTL was measured on a map. MH status was assessed by the SF-36 Health Survey, which was scored on a 0-100 point scale, and an individual with a score of 52 points or less was defined as having poor MH. Logistic regression models were used to examine the association between the distance from the subjects' residence to the closest HVOTL and MH status. The prevalence of poor MH was 15%. Among the 223 subjects, 10 lived within 100 m of a HVOTL. The adjusted odds ratios (OR) for poor MH among those who lived 101-300 m or within 100 m from HVOTL were 1.29 (95% confidence interval (CI): 0.35-10.13) and 1.87 (95% CI: 0.35-10.13), respectively, against the reference category (300+ m). MH status was not significantly associated with the distance between the subject's residence and the closest HVOTL.