Background: Illness beliefs are important determinants of self-management behaviors (SMBs). Spousal or informal caregiver involvement improves clinical outcomes in non-cancer survivors with chronic diseases. However, very little is known about the influence that caregivers have on comorbid disease SMBs in cancer survivors. In this study, we aim to understand and identify concordance in illness beliefs and perceptions between caregivers and prostate cancer survivors and to determine their impact on hypertension (HTN) SMBs. Methods: Survivors and their caregivers completed surveys assessing their beliefs and perceptions and SMBs regarding survivors’ HTN. Both survivors and caregivers answered the Brief Illness Perception Questionnaire (BIPQ) to assess beliefs and perceptions of survivors’ HTN. The BIPQ score is a sum of eight questions with a higher sum score indicating a more threatening view of the illness. Survivors reported adherence to SMBs using the Medication Adherence Report Scale (MARS) and Hypertension Self-Care Activity Level Effects (HSCALE). MARS scores >4.5 were considered adherent. The HSCALE isdivided into five sub-scores – diet, physical activity, smoking behavior, weight management and alcohol intake and each was score was dichotomized. Cohen’s Kappa statistic assessed concordance between survivor and caregiver dyad responses to the BIPQ. Logistic regression assessed associations between survivor and caregiver BIPQ scores and odds of SMB adherence. Results: This analysis included 55 dyads. Mean age of survivors was 70.4 years ± 9.6; 12 (22%) were Black, 36 (65%) were White, 2 (4%) were Asian and 3 (5%) were other race. Mean age of caregivers was 64.4 years ± 10.5, 9 (16%) self-identified as Black, 35 (64%) White, 2 (4%) Asian and 3 (5%) other race. Survivors and caregivers had fair agreements about how much HTN affected survivors’ lives (k = 0.147, p = 0.008), how concerned survivors are about their HTN k = 0.130, p = 0.014), and HTN’s emotional impact on survivors (k = 0.185, p = 0.002). However, survivor-caregiver concordance about HTN had no significant impact on survivors’ SMBs. In contrast, caregivers’ beliefs about HTN was associated with survivors’ SMB such that a 1-point increase in caregiver’s BIPQ score was associated with 8% increase in the odds of survivors’ self-reported weight adherence (p = 0.0314). Survivors’ HTN beliefs were not associated with adherence to SMBs. Conclusions: Caregivers have a significant influence on prostate cancer survivors’ adherence to weight-related SMB, demonstrating that it is important to also educate caregivers who support cancer survivors with chronic comorbidities. Future analysis will include a larger cohort to better understand the interrelationship between caregivers’ illness beliefs and survivors’ SMBs and may help clinicians better direct interventions to improve survivorship outcomes.