In most diseases, concurrent exposure to antibacterial is essential. The purpose of this research is to determine how co-administration of the antibiotics gentamicin (an aminoglycoside) and tigecycline (a tetracycline) affects the liver of rats. Rats received distilled water, tigecycline 7 (TIG 7), tigecycline 14 (TIG14), gentamicin (GEN), tigecycline 7 + gentamicin, and tigecycline 14 + gentamicin groups. After 10 days, TIG and/or GEN caused tissue damage that is seen in considerable biochemical changes in assays of liver functions. Also, a significant elevation of AST, ALT, ALP, cholesterol, and a significant decrease in albumin after TIG or GEN treatment when compared to control groups were observed. A considerable increase in these parameters was observed following TIG and GEN combination. Besides this, there were noticeable pathological alterations in the tissues of the liver. In addition, after TIG and GEN treatment, there is a considerable overexpression of PCNA in the tissues of the liver. As a result, TIG and GEN therapy administered together caused more evident liver damage than either therapy administered individually. According to the findings overall, using TIG and GEN simultaneously in clinical practice is concerning, so it should be done with caution to prevent synergistic negative results.