Aim This study assessed correlations between systemic disturbances of paediatric chronic liver diseases (CLD) and oral symptoms in subjects aged 2–18 years. Methods It was carried out during outpatient appointments at the Children's Memorial Health Institute, Warsaw, Poland, from 2010 to 2015 and comprised 52 CLD patients with a mean age of 12.3 ± 4.6. We also recruited 54 generally healthy controls with a mean age of 12.0 ± 3.7 from the Department of Paediatric Dentistry at the Medical University of Warsaw. The study used various measures, including the Child–Pugh score, which assesses CLD prognosis. We also assessed the causes of liver disease and the medication taken by the patients with CLD. Results A total of 24 patients received a Child–Pugh score of seven or more points, while 28 patients were awarded five or six points. More severe cases of gingivitis and a greater prevalence of oral lesions were evident in patients suffering from liver disease. Oral candidiasis, telangiectasia, bald tongue, cracked strawberry lip, yellowish‐brown gum discoloration, petechiae and gingival bleeding all correlated with the severity of liver dysfunction, coagulopathy, protein, bilirubin and creatinine levels and portal hypertension. Conclusion This study found that oral lesions and gingival bleeding may indicate the progression of liver failure.