["Little information exists about how cognitive impairment in multiple sclerosis (MS) patients impacts on their caregivers' health-related quality of life (HRQoL).", "The objective of this paper is to examine the extent to which cognitive impairment in MS patients contributes to caregivers' HRQoL.", 'A total of 63 MS patients, 63 caregivers and 59 matched controls were recruited. Patients and controls underwent a neuropsychological assessment, including tests of working memory, speed of information processing, executive function, and verbal fluency. HRQoL of the caregivers was assessed by CAREQOL-MS. In logistic regression models, we adjusted for the effects of confounding variables. In these models, the dependent variable was the CAREQOL-MS (higher median of CAREQOL-MS (worse HRQoL) vs. lower median of CAREQOL-MS (better HRQoL) (reference)), and the independent variable was the impairment on each neuropsychological test vs. its integrity (reference).', 'Cognitive impairment in MS patients was significantly associated with worse caregiver HRQoL (adjusted odds ratio (OR) = 3.10, 95% confidence interval (CI) = 1.07-11.55, p = 0.04). In secondary analyses in which each neuropsychological test was entered in the analyses separately, only Symbol Digit Modalities Test (a measurement of information processing speed) impairment (OR = 4.22, 95%, CI = 1.16-14.53, p = 0.03) was significantly associated with worse caregiver HRQoL.'] Does cognitive impairment in patients with multiple sclerosis predict worse caregiver 's health-related quality of life?