Paracetamol has properties that make it useful in many kinds of drugs that are readily available to users. These drugs are often used for extensive periods of time without a doctor's supervision, which might lead to unexpected overdose. The aim of this work was to assess the extent of liver damage in rabbits after administering them with paracetamol for approximately 2 months. The results we obtained suggest that paracetamol administered for a long time causes liver function impairment. It was, however, not possible to determine the impairment by measuring the activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT) or gamma-glutamylotranspeptidase (GGTP). It was determined by measuring the concentration of ketone bodies and arterial ketone body ratio (AKBR) value. Even when taken in small doses, paracetamol causes changes in liver metabolism when taken for an extended period of time.