Introduction:Liver plays an important role in the metabolism of thyroid hormones, as it is the most important organ in the peripheral conversion of tetraiodothyronine (T4) to triiodothyronine (T3) by Type 1 deiodinase.Materials and Methods:This case–control study included 100 decompensated liver cirrhosis patients (71 males and 29 females) and 100 apparently healthy controls (71 male and 29 female). Serum FT3, FT4, and thyroid-stimulating hormone (TSH) levels were measured using electrochemiluminescence immunoassay and analyses between cases versus healthy controls (Group 1) and further analyses in subgroups, cirrhosis with hepatic encephalopathy (HE) cases (n = 38) versus cirrhosis without HE cases (Subgroup 1), cirrhosis survivors (n = 84) versus cirrhosis nonsurvivors (Subgroup 2), HE survivors (n = 23) versus HE nonsurvivors (Subgroup 3). Results were also analyzed for severity of liver disease according to Child–Turcotte–Pugh (CTP) (Class A, B, and C), model for end-stage liver disease (MELD) score, and HE grades.Results:Most common etiology was alcohol (46%) and presentation was gross ascites (74%). Cirrhosis patients had statistically significant lower level of FT3 (P < 0.0001) and FT4 (P < 0.0001) but had higher level of TSH (P < 0.0001) compared with the controls. Cirrhosis with HE (n = 38) had significantly lower lever of FT3 (P < 0.0001) compared with cirrhosis without HE (n = 62), whereas there was no statistically significant difference in FT4 (P < 0.09) and TSH (P < 0.60) levels. FT3 level significantly low in HE Grade 4 patients compared with HE Grade 1 patients (P = 0.0001). In all cirrhotic patients, FT3 and FT4 were negatively correlated, but TSH level was positively correlated with total leukocyte counts, serum total bilirubin, aspartate transaminase, alanine transaminase, globulin, prothrombin time (PT), blood urea, serum creatinine, CTP, and MELD score. Overall, the most common abnormality seen was low T3 (low FT3) syndrome 41% (41 out of 100) in cases, 50% (19 out of 38) in cirrhosis with HE, and 32% (5 out of 16) in Non-survivors cases.Conclusion:The mean FT3 and FT4 levels were significantly decrease and mean TSH levels were significantly increase in liver cirrhosis patients compared to healthy controls. Level of FT3, FT4, and TSH also correlate with the severity of liver disease, level of FT3 can be used as prognostic marker for liver cirrhosis patients.