Purpose: This 1-year prospective study evaluated the implant success rate and peri-implant tissue response of narrow (3.0 mm) implants that were immediately provisionalized at maxillary and mandibular incisor sites. Materials and Methods: Immediate provisionalization of single 3.0-mm diameter implants was performed in patients who fulfilled the inclusion/exclusion criteria. Implant success, marginal bone level (MBL), marginal bone level change (MBLC), Periotest value (PTV), modified Plaque Index, modified Bleeding Index, and Papilla Index Score (PIS) were evaluated immediately after implant placement and at 3, 6, and 12 months after surgery. All surgical and prosthetic complications were recorded. The data were analyzed statistically at a significance level of α =.05. Results: Seventeen implants were immediately provisionalized in 13 patients with missing maxillary lateral incisor(s) and/or mandibular incisor(s). The implant success rates at 1 year were 100% (17/17). The mean MBL values at 0, 3, 6, and 12 months were -0.03 ± 0.06 mm, -0.28 ± 0.35 mm, -0.28 ± 0.32 mm, and -0.38 ± 0.36 mm, respectively. The mean MBLC from 0 to 12 months was -0.35 ± 0.35 mm. The mean PTV at 3 months (-2.65) was significantly lower than that at baseline (-1.59). No significant differences in plaque or bleeding indices were observed over time. A slight but significant increase in PIS over time indicated that the implant papillae were stable and well maintained. All complications were prosthetically related (seven fractured provisionals, two debonded provisionals, three loosened provisional abutment screws) and occurred within the first 3 months after surgery. Conclusions: This 1-year prospective study showed a favorable implant success rate and peri-implant tissue response with immediately provisionalized 3.0-mm diameter implants replacing single missing maxillary and mandibular incisors. While prosthetic complications during the provisional phase were common, they were easily resolved without further consequences. Schlagwörter: dental implant, immediate provisionalization, narrow implant, peri-implant tissue response, prospective study