Tuberculosis (TB) is one of the most common infectious diseases caused by Mycobacterium tuberculosis.  The wide prevalence of tuberculosis all over the world makes it social and economical burden especially for developing countries and the use of anti tuberculous drugs is an optimistic approach for this problem.Certain adverse reaction associated with antituberculosis use need to be properly evaluated especially antituberculosis treatment  induced liver injury and the hepatotoxicity. OBJECTIVES: Assessment of the severity and frequency of liver injury and hepatotoxicity caused by different anti-tuberculosis treatment drugs. METHODS: Seventy five patients randomly selected from newly diagnosed TB patients referred to Abo-Seta hospital in Tripoli, Libya for treatment during period from 1 January to 30 June. All patients received Directly Observation Treatment for Short period (DOTS) antituberculosis regime. Blood samples for liver function tests were obtain before starting the treatment and monthly assessment after starting the treatment for 6 months. RESULTS: In our study the patients developed ATT induced hepatotoxicities by increasing of all three enzymes 43.9% For alanine amino transferase (ALT), 36.6% for AST and 44.6% for ALK. Serious liver dysfunction in the first month compare with control sample, 36.25 ± 1.39 U/L, after one month increased to  64.6 ± 3.55 U/L, n= 75, (P <0.05) from the sample before treatment. Alkaline phosphatase (ALP) shows increase after one month of treatment from 156.17 ± 21.35 U/L, after one month 281.83 ± 45.8 U/L, n= 75, (P < .05). CONCLUSIONS: There is significant increase in liver enzymes after starting of DOTS regime.