This study aimed to investigate the preliminary results achieved with a modified distal first metatarsal osteotomy (reversed L-shaped) for correction of moderate and severe hallux valgus deformities. This prospective study included 31 patients (39 feet) with a mean age of 56 years. All patients underwent a reversed L-shaped osteotomy of the first metatarsal. At follow-up all patients were reviewed clinically and radiologically. Patients were categorized into two groups (MTP angle A: < 20 degrees, and B: 20-40 degrees). The AOFAS score improved from 53 points to 91 points at follow-up (p < 0.0001). Group A showed an increase from 56 to 90 points (p = 0.003), group B from 52 to 92 points (p < 0.0001). The mean 1-2-inter-metarsal angle (IMA) decreased from 12.5 degrees preoperatively to 8 degrees at follow-up (p < 0.005): from from 11 degrees to 9 degrees in group A (p = 0.09) and from from 13 degrees to 7 degrees in Group B (p < 0.0001). No nonunion or avascular necrosis was observed. One diabetic patient developed a resistant postoperative infection. The L-shaped osteotomy provided good and excellent clinical as well as radiological results in the mild and moderate-to-severe hallux valgus deformities treated. The mid- and long-term effect of this type of osteotomy needs to be further investigated.