Background: Knowledge of the relationship between men's health and violence is flawed by narrow and faulty conceptualization and measurement of violence that often results in attribution of health problems to one form or type of violence without consideration of other exposures. Our purpose is to describe the development and initial testing of the Cumulative Lifetime Violence Severity scale designed for use in health research to measure men's perceptions of the severity of their cumulative lifetime violence. Methods: We framed the dimensions of violence severity as: type (physical, psychological, sexual), timing (childhood, adulthood), focus (perpetrator, target), context, frequency, and degree of distress. Items reflecting these dimensions were vetted by local experts including individuals who identified as men, with particular attention to meaningful language for men. The measure was pretested, revised to 64 items, and tested for test-retest reliability prior to use in a study of 685 English-speaking Eastern Canadian men, ages 19 to 65 years. We used Principal Components Analysis to illuminate the underlying dimensionality of the items. Results: Principal Components Analysis yielded a 44-item 11 component solution that accounted for 64.06% of variance with good model fit and a Cronbach's alpha of .92. All dimensions of our conceptualization of violence severity were reflected in the components, except Adult Target Sexual Violence. Convergent validity between the Cumulative Lifetime Violence Severity-44 Scale and a global lifetime violence rating scale was r = .750 (p < .001) and concurrent validity was moderate and significant between the Cumulative Lifetime Violence Severity-44 scale and measures of mental health problems commonly experienced by people with violence histories. Conclusions: The Cumulative Lifetime Violence Severity-44 scale shows promise as the first comprehensive measure of cumulative lifetime violence for health research that considers gender, individual distress and experiences as both perpetrator and target. Next steps include further exploratory analysis with a more diverse sample of men and confirmatory factor analysis.