Parastomal hernia is the most common local stoma complication. The incidence of parastomal hernia reaches 48%, and in a certain proportion of patients it is considered to be an inevitable consequence of stoma formation. The current classifications of parastomal hernias (Rubin, Devlin) are of little clinical value, which is supported by the fact that they have not been used in any publication presenting surgical treatment results in parastomal hernia. Moreover, these classifications do not include recommendations regarding surgical approach selection in those cases where surgical treatment is indicated. These disadvantages clearly indicate a need for developing a new classification of a greater practical value.The aim of the study was to present a suggested new parastomal hernia classification, based on structural criteria, and its use in surgical approach selection.Material and methods. The authors presented a group of 52 patients registered in Outpatient Stoma Clinic at Bielański Hospital in Warsaw, who had been diagnosed with parastomal hernia, defined as a type of hernia associated with postoperative artificial external intestinal fistula, who also had indications for surgical treatment of this stomal complication. These patients underwent a reconstructive procedure of their parastomal hernia with a surgical technique involving the placement of a monofilament polypropylene mesh in the preperitoneal space and repair of co-existing stomal complications using the variants of surgical techniques adequate for a given parastomal hernia type. Based on our studies and clinical experience, we propose a new classification of parastomal hernias, based on structural criteria. All hernias were divided into four groups (type I-IV) depending on hernia size and the presence of hernia in the postoperative scar. Qualification of a given hernia to a specific type was achieved based on physical examination, which makes the suggested classification a simple tool, useful in everyday practice. Each parastomal hernia type requires selecting a suitable surgical approach.Results. In the study group, 44 patients were diagnosed with primary hernia, and 8 - with recurrent hernia. In one case of recurrent hernia it was another recurrence. There were 11 type I hernias, 7 type II hernias, 24 type III hernias, and 4 type IV hernias in the study group. No statistically significant relationship between the type of hernia and the sex of the patients was observed for p = 0.05. However, there was a significant difference between the BMI values and individual hernia types. Patients with type I hernia had the lowest mean BMI value and patients with type IV hernia had the highest mean BMI value. The mean duration of postoperative follow-up was 58 months. There were 5 cases (9.6%) of parastomal hernia recurrence in the study group. A statistical analysis of the results showed that parastomal hernia types identified based on structural criteria differ from one another in parameters such as BMI, indications for surgery, or recurrence rates.Conclusions. The new classification of parastomal hernias is a simple way of identifying patients who require a different therapeutic approach. Thus, it has a practical application as it helps to select a suitable surgical technique. It may be also used for identification of homogeneous groups of patients and therefore allows for a reliable and objective comparison of treatment outcomes.