Background: Men between the ages of 20 and 34 years are at highest risk for testicular cancer yet many lack knowledge and confidence in performing self-examination. The Self-Efficacy to Perform Testicular Self-Examination Scale (SEPTSES) is a 7-item questionnaire to be completed by men, which is designed to measure their confidence in self-examining their testicles. The purpose of this methodological study was to determine the validity and reliability of this self-report measure. Methods: Content validity of the scale and clarity of items were established with a panel of experts. The SEPTSES and three valid scales of related constructs were completed by two samples of men (homeless [n = 150] and non-homeless [n = 156]) aged 18-34 years. Results: A single factor explained 51.5% of the variance of the scale and Cronbach's alpha was satisfactory (a = 0.84). Construct validity was further supported by significant correlations with the other three scales; further support was established by a significant difference in mean scores between the two samples [t (303) = À5.44, p < 0.001]. Conclusion: The SEPTSES is a valid, unidimensional scale and it can be used in further research and in clinical practice as an assessment of this aspect of men's health.