Aim –  To study the serial changes in serum ammonia level in a patient of liver disease with neuropsychiatric manifestation and prognostic predictor in hepatic encephalopathy.   Material and Methods :–  59 diagnosed cases of lives cell dysfunction admitted to medical college at Kolhapur were studies with prospective study.Clinical features,lab parameter mainly serum ammonia levels and outcome were evaluated in all patients with hepatic encephalopathy.   Results :–  Among 59 cases of hepatic encephalopathy 11% were hyperacute,48% were acute,24% were sub acute and 15% chronic cases. And in these cases serum ammonia levels were seen higher in hyper acute and acute stages whereas in subacute and chronic cases it goes on reducing.   Conclusion:–                 Levels of serum ammonia level below 87µmol/lit is the prognostic indicator and high chances of improvement. Levels above 115µmol/lit  have irreversible prognosis and mostly found in comatose state.