To study the qualitative changes in testis tissue after carbon tetrachloride (CCl4) administration and to determine whether citric acid (CA) has a protective effect against testis damage induced by CCl4. This study compared two types of CA by measuring the histoarchitecture of the testis and serum levels of progesterone, estrogen and testosterone on mice. One of the most produced organic acid is citric acid. In this study, CA produced by microbial fermentation using Aspergillus Niger 5mg/kg and derived from citrus limon 400mg/kg (lemon). Mice were treated with daily intraperitoneal (i.p.) injection for seven successive days after randomly separated into six groups: (1) control, (2) CCl4 (0.02%), (3) limon citric acid (400 mg/kg), (4) CCl4 (0.02%) plus limon CA (400 mg/kg), (5) Aspergillus Niger citric acid (5 mg/kg), and (6) CCl4 (0.02%) plus Aspergillus Niger CA (5mg/kg). Mice were sacrificed, then the testes were histopathological examined under light microscopy, serum levels of progesterone, estrogen and testosterone tested. Histopathological results indicated that CCl4 severely damage to mouse testis tissues, however, the protective effects on testes was observed when CCl4 combined with CA. Hormone estimation results showed that the treatment of CCl4 exhibited reduction in testosterone level of serum as compared to the control group of mice, in contrast exhibited high in the level of estrogen and progesterone in CCl4 treated group in correlation to that of the standard control group. Sex hormone serum levels were improved by lemon citric acid (CA) and Aspergillus Niger citric acid but did not reach the mean control level