PURPOSE: We analyzed gender differences in health-related quality of life (HRQoL) and associated factors between informal male and female caregivers in Spain. It is important because of growing rates of dependent people and dwindling public resources. METHODS: We conducted a cross-sectional study of 610 informal caregivers (265 male and 345 female) using an ad hoc structured questionnaire. We performed a descriptive analysis and used multivariate logistic regression to analyze the risk of poor HRQoL, measured with the EQ-5D-5L, according to caregiver sex, sociodemographic characteristics of caregivers and dependents, caregiving circumstances, and support received. RESULTS: Male caregivers were older than women were, and cared more often for their partners. More women used family caregiving allowance (FCA), respite care services, and counseling services, while more men used paid help, home help, and other forms of instrumental help. Women had worse HRQoL than men, particularly in the pain/discomfort dimension. In addition to older age and poor previous health, caring for a partner (OR = 2.379), for a person with major dependence (OR = 1.917), low social class (OR = 1.634), and low social support (OR = 2.311) were factors associated with poor HRQoL. Receiving FCA was associated with better HRQoL (OR = 0.319). Controlling for all these variables, women had 131% more odds than men to have poor HRQoL. CONCLUSIONS: Male and female caregivers in Spain differ in received support and how their HRQoL is affected. These differences are important to design interventions to promote more equitable sharing of care responsibilities and better caregiver health.