Purpose: There is wide variability in how spouses providing care respond to their care situations. Few studies focus on the roles of both intra- and interpersonal factors in long-term spousal care, particularly in the context of Parkinson's disease (PD). The current study uses longitudinal data over a 10-year period to examine the roles of optimism, pessimism, mutuality, and spouse gender in predicting role strain in PD spouses. Design and Methods: A longitudinal design was used to study 255 spouses of persons with PD over a 10-year period, with data points at baseline (Year 0), Year 2, and Year 10. A series of multilevel models were used to examine four role strain variables--global strain, strain from worry, strain from feelings of being manipulated, and strain from increased tension. Results: Female spouse gender predicted both higher Year 10 role strain and faster increases in role strain over the 10-year period. In addition, high mutuality and optimism and low pessimism at baseline played important protective roles against increased role strain at Year 10. Implications: This study focused on early-stage spousal care in a primarily physical disability context. Findings suggest that gender differences place wives at greater risk for negative outcomes, even in the absence of dementia. Additionally, clinicians have opportunities to target interventions early in the care trajectory based on intra- and interpersonal risk factors.