The Cross-Sectional study was carried out for a period of six months, from June (2020) to December (2020). 283 patients were visited a dental clinic in Hilla city suffering from dental caries. All these samples were inoculated for isolated pathogenic bacteria by identification of these bacteria by gram stain, biochemical test and compact Vitek 2 system. Out of (283) clinical samples, only 250 (88.3%) positive culture, whereas 33 (11.6%) samples showed no bacterial growth, which may be treated with antibiotics or the presence of other types of causative agents that might need special technique for their detection, such as viruses and fungus. Thus, Gram-positive bacteria were about 47% of the total isolates, whereas Gram-negative bacteria comprised about 53% of the total isolates (52.8 percent). The predominant gram-positive bacterial species found in dental caries was Streptococcus mutans, found in 45 individuals (18 percent of the samples), followed by Streptococcus epidermidis, found in 26 people (10.4 percent), Streptococcus pneumonia, found in 23 people (9.2 percent), Staphylococcus aurous, found in 19 people (7.5 percent), and Streptococcus oralis, found in 5 people (2.3 percent) (2 percent). In addition, Lactobacillus acidophilus was the most common negative bacterial species isolated from dental caries. It was found in 40 (16%), followed by Fusobacterium nucleatum 41 (91.11%), E. coli 35 (14%), 5 (2%) were found for each Campylobacter jenjuni and Klebsiella pneumonia, and 3 (1.2%) were found for each Pseudomonas aeruginosa and These bacteria found in all isolates were identified by the compact Vitek system. The Antibiotic Susceptibility Test for Gram Positive and Negative Grams Bacterial isolates were investigated. The results were compared according to the compact Vitek 2 system as susceptible, intermediate and resistant. It has been found that most Gram-positive and Gram-negative isolates are highly resistant to beta lactam groups. It was found that Streptococcus mutans was resistant to Penicillin at a rate of (82.2%). In addition, these isolates were highly sensitive to Amoxicillin and Ciprofloxacin at a rate of (86.6%) and (71.1%) respectively. Streptococcus epidermidis was highly resistant to Tetracycline at 88.4% and highly sensitive to Amoxicillin at the same rate. The results of this study showed that Streptococcus pneumonia was highly sensitive to Gentamycin, Ciprofloxacin, Cefotaxime, Amoxicillin and Vancomycin at a rate of 78.2%. Staphylococcus aurous were tested for antibiotics. It was found that these bacteria were highly sensitive to Meropenem (94.7%). Streptococcus oralis was highly resistant to Imperium (100%), and highly sensitive to Gentamycin, Ciprofloxacin, Cefotaxime, and Amoxicillin. In addition, gram negative bacteria were studied for antibiotic testing. It was found that E. coli was highly sensitive to Gentamycin, Imperium, Amoxicillin and Vancomycin (91.4%), while Fusobacterium nucleatum was highly sensitive to Ciprofloxacin (95.12%). Campylobacter jenjuni, Pseudomonas aeruginosa, Klebsiella pneumonia and Proteus mirabilis were highly sensitive to most antibiotics used in this study. Finally, Lactobacillus acidophilus was highly resistant to Penicillin in rate (82.5%) and sensitive to Ciprofloxacin in rate (88.5%).