Objective: The implant metal for minimally invasive repair (Nuss procedure) of pectus excavatum (PE) often causes metal allergy and postoperative infection. Titania/chitosan has anti-allergy and anti-inflammatory effects. This study was conducted to evaluate the effects of titania/chitosan on Nuss repair of PE patients with stainless steel. Methods: A total 828 PE patients were recruited and randomly assigned into two groups: one group received Nuss repair using stainless steel (SS group) and another group using stainless steel coated by Titania/chitosan (SSTc group). Infection rate, metal allergy and Haller Index were measured. The presence of overt infection was evaluated by measuring serum levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Results: After mean 24-month Nuss repair, postoperative infection occurred in 26 cases (6.3%) and 2 cases (0.5%) in SS and SSTc groups (P < 0.05), respectively. On the other hand, 14 cases (3.4%) and 0 case (0%) suffered from bar allergy for implant metal in SS and SSTc groups, respectively (P3.0 cm needing reoperation in SS and SSTc groups (P < 0.05), respectively. After surgery (18-34 month), serum levels of ESR and CRP were higher in SS group than in SSTc group in non-infected patients (P < 0.05). Comparatively, the serum levels of ESR and CRP were significantly higher in SS group than in SSTc group in infected patients (P = 0.01). Conclusion: The stainless steel coated by Titania/chitosan provides a safer and more effective material for Nuss repair of PE by reducing the metal allergies, infection rates and reoperation rates.