Purpose Survivors of critical illness often suffer from reduced health-related quality of life (HRQoL) due to long-term physical, cognitive, and mental health problems, also known as post-intensive care syndrome (PICS). Some intensive care unit (ICU) survivors even consider their state of health unacceptable. The aim of this study was to investigate the determinants of self-reported unacceptable outcome of ICU treatment. Methods Patients who were admitted to the ICU for at least 48 h and survived the first year after discharge completed validated questionnaires on overall HRQoL and the components of PICS and stated whether they considered their current state of health an acceptable outcome of ICU treatment. The effects of overall HRQoL and components of PICS on unacceptable outcome were studied using multiple logistic regression analysis. Results Of 1453 patients, 67 (5%) reported their health state an unacceptable outcome of ICU treatment. These patients had a lower score on overall HRQoL (EQ-5D-index value of 0.57 vs. 0.81; p