Objective: To examine the value of posttraumatic headaches in predicting return to work (RTW) in patients with mild traumatic brain injury (MTBI). Setting and Participants: A total of 109 participants recruited from an outpatient head injury rehabilitation center, British Columbia, Canada. Design: Logistic regression analyses of secondary data. Main Measure: The Numerical Pain Rating Scale (NPRS), measure of headache intensity. Nine resulting NPRS scores were used to predict successful versus unsuccessful RTW. Results: The largest effect size [odds ratio Exp(B)] value of 0.474] indicated that the odds of returning to work successfully are more than cut in half for each unit increase in NPRS rating. Conclusion: To the author's knowledge, this is the first study of the impact of headache intensity on RTW for patients withMTBI. Posttraumatic headache severity after MTBI should be taken into account when developing models to predict RTW for this population. Headache intensity may act as a confounding variable for at least some injury characteristics (eg, cognitive functioning) and may add to the inconsistencies in the TBI and MTBI literature. Results may be utilized to guide rehabilitation efforts in planning RTW for patients with MTBI.