Discrepancies between physicians' assessment and patients' subjective representations of the disease severity may influence physician-patient communication and management of a chronic illness, such as multiple sclerosis (MS). For these reasons, it is important to recognize factors that distinguish patients who differently estimate the impact of MS. The purpose of this study was to verify if the patients who overestimate or underestimate the impact of MS differ in their perception of personal resources from individuals presenting with a realistic appraisal of their physical condition. A total of 172 women and 92 men diagnosed with MS completed Multiple Sclerosis Impact Scale, University of Washington Self Efficacy Scale, Rosenberg Self-Esteem Scale, Body Esteem Scale, Brief Illness Perception Questionnaire, Treatment Beliefs Scale, Actually Received Support Scale, and Socioeconomic resources scale. Physician's assessment of health status was determined with Expanded Disability Status Scale. Linear regression analysis was conducted to identify the subsets of patients with various patterns of subjective health and Expanded Disability Status Scale (EDSS) scores. Patients overestimating the impact of their disease presented with significantly lower levels of self-esteem, self-efficacy in MS, and body esteem; furthermore, they perceived their condition more threatening than did realists and underestimators. They also assessed anti-MS treatment worse, had less socioeconomic resources, and received less support than underestimators. Additionally, underestimators presented with significantly better perception of their disease, self, and body than did realists. Self-assessment of MS-related symptoms is associated with specific perception of personal resources in coping with the disease. These findings may facilitate communication with patients and point to new directions for future research on adaptation to MS.