Statement of problem: Post-extraction dry socket is the most painful complication in oral surgery. It is not only time consuming for dentists and patients but also very expensive to treat.Purpose: The aim of this study was to evaluate the role of Irsha antibacterial mouth wash on reduction of dry socket prevalence in patients who referred to Tabriz Oral and Maxillofacial Surgery Department.Materials and Method: A quasi experimental study was conducted on 274 patients (146 in study group and 128 in the control group) with 300 sockets in their extracted teeth. Patients were randomly selected from those referred to Tabriz oral and maxillofacial clinic. Before extraction, the patients in the study group washed their mouth with Irsha mouth wash for 30 seconds to 1 minute and the operator rinsed the site of the extraction by a gauze soaked with respective mouth wash. On 3 rd and 7 th days, they were called to fill the questionnaire. The patients with dry socket were invited to the oral and maxillofacial department and examined by an oral and maxillofacial surgeon. The collected data were statistically analyzed by Chi-Square test, using SPSS soft ware.Results: 2.5% of the patients in the study group and 10.5% in the control group had dry socket ( p = 0.04), so there was a significant difference between the two groups. Influential factors in dry socket appearance such as smoking and oral hygiene condition were studied, showing a significant difference ( p = 0.006 and 0.009, respectively). There was a significant difference between the extracted teeth with preapical lesions and those without any areas in their radiographs. Patients with poor oral hygiene showed more dry socket involvement than good oral hygienic group ( p = 0.006).Conclusion: Irsha antibacterial mouth wash like other antibacterial mouth washes can reduce dry socket prevalence. Bacterial accumulation and their virulence might be a major cause of the dry socket.   Key words: Dry Socket, Alveolar Osteitis, Mouthwash