Objective: In recent years, photodynamic therapy (PDT) using a combination of photosensitizer and laser light source has been used in periodontal therapy. The aim of this review is to provide an overview of the current status and use of PDT. Data Sources: A review of pertinent literature was carried out in PubMED to determine the current position of PDT applications in periodontal and peri-implant diseases. Conclusions: In spite of different results and suggestions from various researchers, the present review showed that use of PDT may help improve periodontal outcomes. Therefore, it could become a new method for antibacterial treatment and may be used as an adjunct to or as conventional therapy for the treatment of periodontal and peri-implant diseases. Based on the results presented herein, there is promising, albeit preliminary, information regarding the benefits of PDT use on periodontal treatment outcomes. However, the conclusions are a reflection of a relatively small sample size and therefore need to be demonstrated in the general population. Clinical Relevance: Periodontal diseases and peri-implantitis are among the specific targets where PDT can be applied. Keywords: dental implants, periodontitis, photodynamic therapy, photosensitizer