In this study, we formally examine the association between penis size dissatisfaction and gun ownership in America. The primary hypothesis, derived from the psychosexual theory of gun ownership, asserts that men who are more dissatisfied with the size of their penises will be more likely to personally own guns. To test this hypothesis, we used data collected from the 2023 Masculinity, Sexual Health, and Politics (MSHAP) survey, a national probability sample of 1,840 men, and regression analyses to model personal gun ownership as a function of penis size dissatisfaction, experiences with penis enlargement, social desirability, masculinity, body mass, mental health, and a range of sociodemographic characteristics. We find that men who are more dissatisfied with the size of their penises are less likely to personally own guns across outcomes, including any gun ownership, military-style rifle ownership, and total number of guns owned. The inverse association between penis size dissatisfaction and gun ownership is linear; however, the association is weakest among men ages 60 and older. With these findings in mind, we failed to observe any differences in personal gun ownership between men who have and have not attempted penis enlargement. To our knowledge, this is the first study to formally examine the association between penis size and personal gun ownership in America. Our findings fail to support the psychosexual theory of gun ownership. Alternative theories are posited for the apparent inverse association between penis size dissatisfaction and personal gun ownership, including higher levels of testosterone and constructionist explanations.