Purpose: To develop valid indicators of stress in individuals with aphasia (IWA) by examining the relationship between certain language variables (error frequency [EF] and word productivity [WP]) and cortisol reactivity. Method: Fourteen IWA and 10 controls participated in a speaking task. Salivary cortisol was collected pre- and posttask. WP and EF were calculated from the language sample elicited during the speaking task. Results: As expected, IWA had less WP and a higher EF than did control participants, and these effects were related to aphasia severity. Cortisol reactivity of IWA was moderately associated with WP, such that those with higher WP showed greater cortisol reactivity. The control group did not demonstrate this relation. Neither group demonstrated a relation between salivary cortisol reactivity and EF. Conclusion: WP in individuals with aphasia holds potential as a behavioral index of stress in this population.