Aims: The aim of the study is to evaluate the prognostic value of Herringñs classiþcation for treatment planning and predicting the þnal outcome of the disease. Methods: We analysed 45 patients treated in our department in the period between 1992 Ð 2000. The analysis consisted of determining the lateral pillar collapse in fragmentation stage and the containment of the femoral head in the residual stage. We did retrospective analysis of the x-rays in fragmentation stage and classiþed the patients according to Herring classiþcation. Group A included 10 patients, group B Ð 20 patients and group C included 15 patients. For analysis of the x- rays in residual stage we used Hayman Ð Herndon Acetabulum Ð Head Index (AHI). The statistical analysis of the results included the analysis of the differences between the lateral pillar collapse among the groups and the differences between affected hip and the contralateral control hip. Correlation between the degree of lateral pillar collapse and the AHI in the residual stage was also analyzed. Correlation between the age of onset of the disease and AHI was determined for each group, too. Results: The results show signiþcant differences between the lateral pillar collapse in Herring groups, and among the affected and control hips. Differences of AHI values were also signiþcant between the groups. Correlation between the AHI and lateral pillar collapse for each group shows moderate connection just as the one between AHI and age. Conclusions: Herringñs classiþcation is reliable in classifying patients with Perthes disease. It enables good prediction of the natural course of the disease and thus inßuences the treatment decision-making.