The United States is experiencing a severe shortage of Emergency Medical Service (EMS) paramedics. The job outlook for paramedics (EMT-P) for the years 2012-2022 is predicted to increase by 23%-33%, which is much faster than the 4% average increase of other first-response professions. The average tenure of paramedics is less than 4 years. There is a significant gap in the literature concerning paramedic personality traits and tenure. The primary objective of the current study is to provide empirical data on the personality traits possessed by long-term paramedics (5+ years), and compare them to those with shorter tenure (< 5 years). Using Allport's Trait Theory, I predicted that personality would affect paramedic longevity. The 6 personality traits tested were warmth, reasoning, emotional stability, liveliness, social boldness and openness to change. A socio-demographic questionnaire, determined the length of their EMS career, while the 16PF® Assessment, tested their personality traits. Using t tests, Mann-Whitney U tests, and a set of regression analyses, data were examined to determine if length of career and personality traits predicted paramedic tenure. The research sample consisted of long term paramedics and former paramedics. The results showed that of the 6 personality traits, only warmth was a significant predictor of paramedic tenure. A logistic regression showed for every additional point in warmth, the odds of leaving EMS prior to 5 years increased by a factor of 2.77. This study provides support for positive social change by helping EMS to learn how to increase recruitment and tenure. It also helps by advising EMS agencies to attend to the mental and emotional health of their paramedics by being aware of the level of their warmth personality trait.