Abstract Purpose of the study Available studies on Scarf osteotomies of the first metatarsal (M1) and first phalange (P1) shortening and varus displacement have reported good results, but have have not focused on complications. We reviewed a consecutive series of 475 feet operated on over a five year period. Our goal was to determine the incidence of complications and to compare our data with reports in the literature. We wanted to know if association with Weil osteotomy on the lateral metatarsals affects the rate of complications. Material and methods We used the following inclusion criteria: hallux valgus > 35°, adult subject, with or without impact on the lateral ray, no prior foot surgery, no systemic disease, no other co-morbid condition. We distinguished two groups: group 1 with isolated first ray disease, and group 2 with hallux valgus and lateral metatarsalgia requiring surgery. Results We determined the incidence of each complication. Metatarso-phalangeal joint (MTP1) stiffness was the most frequent complication: incidence declined with postoperative time: 41.7% at day 35, 5.7% at day 120. The joint was very stiff with defective pulp weight-bearing in 1.3% of the feet at 12 months. Late wound healing was observed in 5.7% of feet and secondary osteotomy displacement in 1%. Incidence of other complications, including operative site infection, was less than 1%. General complications were: reflex dystrophy (1.3%) and deep vein thrombosis (0.6%). Excepting a longer period of postoperative stiffness, we were unable to identify any change in the rate of postoperative complications in feet with an associated Weil osteotomy of the first ray. Discussion Our findings confirm that Scarf M1 osteotomies with varus shortening of P1 generates fewer complications than the techniques used earlier. Certain complications have disappeared: nonunion after M1 and P1 osteotomy, great toe claw, symptomatic iatrogenic hallux valgus. Complications with a very low incidence in all series are: operative site infection, osteonecrosis of the M1 head, fracture of M1 at weight bearing. Notching of the two osteotomy pieces with elevation of the metatarsal head and transfer metatarsalgia has been reported by authors using short diaphyseal osteotomies. A stiff MTP1 remains the most frequent complication. Overtly stiff joints (30% loss of range of motion) were observed in 4.6% of our patients at 12 months; 1.3% had major stiffness (20° extension, 0° plantar flexion). This stiffness has been reported by others using the same technique but the risk factors have not been identified. Conclusion This prospective work enabled us to establish the rate of secondary complications of first ray surgery for M1 Scarf osteo-tomy and P1 osteotomy. Complications are rare, a further argument favoring use of these osteotomies. This statistical study enables us discuss the risk of complications at the preoperative interview, keeping in mind the specific elements inherent in each particular situation.