The Muller muscle-conjunctival resection is a common technique used to treat blepharoptosis, but there is variability with the target surgical resection and expected postoperative outcomes measured by marginal reflex distance-1 (MRD1). A Levator-Mullerectomy is a novel surgical approach described by Morris et al to incorporate the levator palpebrae superioris in the same incision as the classic Muller muscle-conjunctival resection in the treatment of blepharoptosis. This a retrospective study of patients who underwent Levator-Mullerectomy for ptosis repair showing the clinical outcomes based on MRD1. Statistical analysis was performed using analysis of variance and a nonparametric Kruskal-Wallis test. One hundred-twelve eyes of 83 patients (29 bilateral cases) with a mean age 64.6 years (7-92 years) were included. The types and prevalence of blepharoptosis were involutional (83%), neurogenic (8.0%), traumatic (3.6%), apraxia (2.7%), and congenital (2.7%). There was no significant difference in clinical outcome based on type of blepharoptosis (P = 0.7). Target resection lengths of 8 mm, 10 mm, and 12 mm were compared with postoperative MRD1 change. The mean change in MRD 1 between 8 mm and 10 mm was found to be statistically significant (P = 0.001 for both) but was not statistically significant for the 12 mm resection (P = 0.8). In patients with blepharoptosis and a positive response to 2.5% phenylephrine can benefit from Levator-Mullerectomy with either an 8 mm or 10 mm resection. This novel surgical approach allows surgeons to produce a more predictable and consistent clinical outcome.