Background Conventional frontalis transfer may cause a range of complications. In order to overcome complications, we made modifications to the surgical technique, and compared the outcomes of patients who underwent conventional frontalis transfer with those of patients who underwent modified frontalis transfer. Methods We conducted a retrospective study of 48 patients (78 eyes) who underwent conventional frontalis transfer between 1991 and 2003 (group A) and 67 patients (107 eyes) who underwent modified frontalis transfer between 2004 and 2014 (group B). The frontalis transfer procedures were modified conform to the following principles. The tip of the frontalis muscle flap included soft tissue that was as thick as possible and the soft tissue on the tarsal plate was removed to the greatest extent possible. A double fold was created in cases of unilateral ptosis. In order to evaluate the objective effects of modification, preoperative and postoperative values of the marginal distance reflex 1 (MRD1), the corneal exposure area, and the decrease in eyebrow height were compared between the two groups. Results In group A, patients showed an improvement of 1.19 mm in the MRD1, a 6.31% improvement in the corneal exposure area, and a 7.82 mm decrease in eyebrow height. In group B, patients showed an improvement of 2.17 mm in the MRD1, an 8.39% improvement in the corneal exposure area, and an 11.54 mm decrease in eyebrow height. The improvements in group B were significantly greater than those in group A. Conclusions Modified frontalis transfer showed better results than the conventional procedure and provided satisfactory outcomes.