Endodontic – periodontal lesions are induced by spreading of the pulpal infection to periodontal tissues and/or vice versa. These lesions are complicated for diagnostics and therapy. For their easier management, we have used classification based on the primary cause of disease.The classification system comprises of: primary endodontic lesion, primary endodontic lesion with secondary periodontal involvement, primary periodontal lesion, primary periodontal lesion with secondary endodontic involvement and true combined lesions. Vertical root fracture may mimic the symptoms of true combined lesion. Treatment od endodontic – periodontal lesions includes an adequate root canal treatment with application of calcium hydroxide, sometimes in combination with conservative, non-surgical periodontal treatment. If there is no improvement, additional treatment options include periodontal and endodontic surgery, root amputation and guided tissue regeneration techniques. Correct diagnosis, adequate therapy, host response and patient's oral hygene are essential for good treatment results