To study the caregivers' perception of their own well-being 1 year after subthalamic deep brain stimulation (STN-DBS) surgery in Parkinson's disease (PD) patients, using a qualitative and quantitative approach. 25 patients and caregivers, living together in partnerships, were examined before and at 3-month and 1-year follow-up (FU) after STN-DBS surgery. Semi-structured FU interviews concerning caregivers' own well-being under STN-DBS were conducted and analyzed: caregivers were accordingly assigned to positive or negative outcome groups. Quality of life (QoL), depression, apathy and anxiety of caregivers and patients were measured. These quantitative data were compared to the 1-year FU interview outcomes. Multiple comparisons analyzed caregiver group assignments based on these measurements. Logistic regression was used to find predictors. Additionally, patients' mood ratings were used in multiple comparisons with caregivers' subjective outcome, to analyze the interaction of patient and caregiver ratings. At 3-month FU, caregivers were more indecisive concerning their own well-being than at 1-year FU. At 1-year FU, caregivers from the negative group had greater depression, anxiety and lower QoL ratings. They were significantly older compared to the positive group. Patients' depression showed significantly stronger improvement in the positive outcome group. Patients' apathy and depression ratings were significant covariates of caregivers' QoL. Our results show that at 1-year FU over 50 % of the caregivers rated their subjective well-being as negative. Especially older and more depressed caregivers are at risk. These caregivers and their partners should be monitored more closely to identify possible problems and help them adapt following surgery.