INTRODUCTION: Breast surgery has become less invasive without compromising survival and aimed at improving quality of life (QoL) in terms of satisfaction with cosmesis. Despite that, short-term patient-perceived aesthetic results after breast-conserving surgery (BCS) can still be displeasing. Long-term analysis regarding contentment with cosmesis are lacking and could be different, considering that over time, patients' priorities might change and a different thought-out judgment could be given. The goal of this study is to describe long-term results in QoL after BCS and to identify possible predictors for disappointing aesthetic results. METHODS: In this retrospective cohort study, the long-term outcomes of QoL, patient-reported outcome measurements and aesthetic outcomes were investigated 4.5-10.8 years after BCS. In total, 104 patients received standardized questionnaires from the European Organisation of Research and Treatment of Cancer. The aesthetic results after BCS were evaluated subjectively through a diverse panel of healthcare observers. Objective assessment of the aesthetic results was done using the BCCT.core system of evaluating standardised breast photographs. Factors influencing aesthetic outcome were statistically analysed. RESULTS: QoL was high in around 75% of the patients. Correlation between QoL and aesthetic outcomes was found according to Spearman's correlation (r = 0.262, p = 0.007). Significant factors negatively influencing patient reported aesthetic outcomes were sentinel node procedure (p = 0.016), axillary lymph node dissection (p = 0.004), chemotherapy (p = 0.001), and hormonal therapy (p = 0.001). CONCLUSION: The majority of the patients have acceptable QoL after BCS during long-term follow-up. Unacceptable aesthetic outcomes after BCS are associated with lower QoL and are influenced by sentinel node procedure, axillary lymph node dissection, chemotherapy, and hormonal therapy.