Upper blepharoplasty is the most popular facial cosmetic surgery. Although there are a variety of reasons to undergo this procedure, all patients expect an optimal cosmetic result. However, little is known about the factors that influence satisfaction with treatment outcome. We assessed to what extent patient characteristics, clinician-rated and postsurgical outcome measures, and patient-reported satisfaction with facial appearance and quality-of-life are associated with patient-reported satisfaction with treatment outcome after a primary upper blepharoplasty. This study was performed in 583 patients with an upper blepharoplasty between 2016 and 2021. The primary outcome was satisfaction with treatment outcome 6 months postoperatively using the FACE-Q. Determinants were baseline patient characteristics (demographics), preoperative and postoperative clinician-rated and surgical outcome measures, and preoperative and postoperative FACE-Q appearance and quality-of-life scales. Hierarchical linear regression analysis was used to determine how much of the variance in satisfaction with outcome could be explained by these groups of determinants. A total of 63% of the variance could be explained by the five groups of determinants of which 8% was explained by the baseline patient characteristics and clinician-rated and patient-reported outcomes together, another 8% by the postoperative clinician-rated outcomes, and the remaining 47% by the postoperative patient-reported outcomes. Patient characteristics, clinician-rated outcome measures, and baseline FACE-Q appearance and quality-of-life scores were of limited value in explaining satisfaction with treatment outcome. However, the postoperative FACE-Q appearance scale and the decision to undergo a blepharoplasty were strongly associated with satisfaction with treatment outcome.