Primary cicatricial alopecias (PCAs) are a rare and poorly understood group of disorders that result in replacement of pilosebaceous unit with fibrous tissue which leads to permanent hair loss and therefore significantly affects the quality of life. The aim of treatment, currently, remains to reduce symptoms and to slow or stop PCA progression, namely the scarring process. Early treatment is the key to minimizing the extent of permanent alopecia. The diagnosis and therefore treatment are based on the Classification of scarring alopecia created by a group of experts from the North American Hair Research Society (NAHRS) at a meeting organized in February 2001. The classification is based on a clinical picture and a pathohistological analysis of the biopsies from the active phase of the disease. Scalp biopsy is the key diagnostic test for diagnosis of PCA because it determines the dominant inflammatory infiltration in active phase of the disease. However, pathohistological interpretation of scalp biopsy can be a major challenge for the pathologist, especially in the absence of detailed anamnesis, inadequate samples, inadequate tissue cuts and an inadequately chosen biopsy site. Although it is known that the biopsy should be taken from the edge of the active lesion, not all the follicles on the edges of the lesion are affected by the disease, especially at the early stage, when the changes are barely visible to the naked eye. Tools to increase the diagnostic accuracy of scalp biopsy are needed. The hypothesis of this study is that the trichoscopy is useful in determining the optimal site for scalp biopsies in primary scarring alopecia, thereby increasing the probability of exact pathohistological diagnosis. This study investigated the pathohistological interpretation of 60 primary scarring alopecia, of which 30 were taken from the edge of the lesion and the site was chosen by the naked eye, and in 30 cases the biopsy was guided with dermatoscope. Based on the results of the study it can be concluded that the examination and dermoscopy guided biopsy increases the probability of an exact histopathological diagnosis by 48% compared with examination and biopsy without dermoscopy. The results of additional analyzes showed that there is a good potential of trichoscopy to completely rule out the need for biopsy in terms of confirmatory diagnosis LPP and DLE. To conclude, the results of our study confirmed the important role of trihoscopy in determining the biopsy site in order to confirm the diagnosis of primary scarring alopecia. In addition, the results indicate a clear potential of trihoscopy as a possible diagnostic and not just auxiliary method.