Introduction: Febrile seizures occur in 2-5% of children between six months and five years of age 
and represent the most common convulsive event in childhood. There is a hormone released by the 
pituitary gland, arginin-vasopressin (AVP), has been shown to be involved in the thermoregulatory 
response to fever and convulsions. The C-terminal portion of the AVP precursor, copeptin, has been 
recognized as a robust marker of AVP secretion. Aim of the work: to evaluate the role of serum 
copeptin in differentiation of febrile seizures from other seizures. Patients and methods: The study 
was a prospectivecross-sectional study, conducted on 20 patients presented with febrile seizures , 20 
with epileptic seizures and 2.0 patients with febrile illness without seizure. Results: Our study was 
carried on 80 children who were classified into 4 groups; Group I: included 20 patients with FS. 
Group II: included 20 patients with febrile illness without seizure. Group III: included 20 patients 
with epileptic seizures. Group IV: included 20 apparently healthy, age and sex matched children as a 
normal control. They were randomly selected during the period from January 2016 to July 2016. 
Informed written consents were obtained from the patient's legalguardians before enrollment in the 
study. Discussion : Copeptin is a 39-amino acid, glycosylated peptide, and the C-terminal part of 
provasopressin, the precursor of arginine vasopressin (AVP), which is an antidiuretic hormone from 
the hypothalamus. Copeptin is secreted from pituitary gland together with AVP after hemodynamic 
and osmotic stimuli. Since AVP is unstable and unfit to be used as a biomarker, copeptin instead used 
in the place of AVP because of its molecular stability, easier testing methods and faster results. 
Recommendation: The measurement of serum copeptin is better suited for the diagnosis of FS.
Future studies.