Abstract Background and Aims Patients on hemodialysis (HD), are a clinically vulnerable population. We analyzed changes in the results of the KDQOL™-36 questionnaire carried out in 2019 vs 2021, during Covid-19 pandemic. We have related the results to demographic and analytical parameters, BCM, modality and dose of dialysis, in addition to having suffered a COVID-19 infection. Method This is a retrospective, observational analysis performed in 47 clinics from Fresenius Medical Care (FMC) Spain. As part of our Healthcare Quality Improvement Program, HRQoL measurements were assessed using the KDQOL™-36 questionnaire. This questionnaire evaluates Physical and Mental Composite Scores (PCS and MCS, respectively) and three disease-specific scales: Effects, Burden and Symptoms dimensions (EKD, BKD, SKD). We focused our analysis in 1000 patients who completed both surveys in 2019 and 2021 in order to analyze differences. We compared results of both surveys by Wilcoxon test. Improvement between 2019 and 2021 was calculated for each QoL Score. We categorized patients based on QoL evolution (improvement vs worsening) and analyzed the relationship between QoL improvement and different variables by univariate and multivariate logistic regression. Non-normal variables were categorized. Results The results are presented in detail in the figures section. Conclusion Except for the PCS, there were an improvement in QoL results in 2021 vs 2019. Women presented a worse evolution in EKD, MCS and SKD scores. In our study, having COVID-19 infection did not seem to be a factor associated with changes in quality-of-life in 2021. Patients on OL-HDF presented an improvement on the SKD scale compared to those treated with conventional therapy. Higher lean tissue index was related with improvement in PCS scale. Age was related with better EKD scale evolution as CCI above 5 was related with MSC Improvement. BKD scale evolution was related with HD vintage.