Purpose: The purpose of this study was to compare illness-related anxiety among participants in the Rituximab Extended Schedule or Retreatment Trial (RESORT) randomly assigned to maintenance rituximab (MR) versus rituximab re-treatment (RR). A secondary objective was to examine whether the superiority of MR versus RR on anxiety depended on illness-related coping style. Patients and Methods: Patients (N = 253) completed patient-reported outcome (PRO) measures at random assignment to MR or RR (baseline); at 3, 6, 12, 24, 36, and 48 months after random assignment; and at rituximab failure. PRO measures assessed illness-related anxiety and coping style, and secondary end points including general anxiety, worry and interference with emotional well-being, depression, and health-related quality of life (HRQoL). Patients were classified as using an active or avoidant illness-related coping style. Independent sample t tests and linear mixed-effects models were used to identify treatment arm differences on PRO end points and differences based on coping style. Results: Illness-related anxiety was comparable between treatment arms at all time points ( P > .05), regardless of coping style (active or avoidant). Illness-related anxiety and general anxiety significantly decreased over time on both arms. HRQoL scores were relatively stable and did not change significantly from baseline for both arms. An avoidant coping style was associated with significantly higher anxiety (18% and 13% exceeded clinical cutoff points at baseline and 6 months, respectively) and poorer HRQoL compared with an active coping style ( P < .001), regardless of treatment arm assignment. Conclusion: Surveillance until RR at progression was not associated with increased anxiety compared with MR, regardless of coping style. Avoidant coping was associated with higher anxiety and poorer HRQoL.