Purpose: Treatment by means of implant-supported immediately loaded fixed full-arch prostheses is known to be related to biologic and technical complications. The aim of this retrospective study was to investigate the prevalence and moment of occurrence of biologic and technical complications happening in immediately loaded fixed full-arch prostheses. Materials and Methods: This study investigated patients who received treatment with immediately loaded fixed full-arch prostheses using four to six implants from 2007 to 2013. The investigation included biologic and technical complications. Complications were depicted regarding their prevalence and their first time of occurrence. Statistical analysis was performed regarding the differences of the mean complication values between the mandible and the maxilla and between technical and biologic complications. Results: The investigation included 482 immediately loaded fixed full-arch prostheses (380 patients, mean observation period: 23.5 months). In 193 arches (40%), either technical (30.9%), biologic (6.5%), or both (3.1%) types of complications occurred. Technical complications occurred significantly more often than biologic complications (P .000). The most frequent technical complication was "fracture of veneering material" (24.7%, arch level). The most frequent biologic complication was "marginal bone loss ≥ 2 mm" (16.3%, implant level). The median first advents of technical complications were after 23/26 months (implant-/prosthesisrelated) and after 3 months for biologic complications, respectively. There was no significant difference of the mean complication rates between the maxilla and the mandible (P = .409). In 99.0% of the arches with complications, the restorations could be obtained. Conclusion: Within this treatment concept, biologic and technical complications may occur over time. However, the vast majority of complications (99.0%) do not affect the overall prosthesis survival. Technical complications are assumed to occur significantly more often than biologic complications. It is suggested that not only stress and material fatigue but also function is a matter concerning this treatment option and, thus, may be a factor related to complication rates. Schlagwörter: immediate function, immediate implants, immediate loading, immediate placement, implant