Background: Hyperthyroidism occurs due to over production of thyroid hormones, one types of hyperthyroidism was Graves, disease. Hyperthyroidism is characterized by high level of serum thyroxin, triiodothyronine and low level of thyroid stimulated hormones. Material and Methods: fifty two hyperthyroid patients, thirty patients under treatment with carbimazole and other twenty two patients under treatment with radioactive iodine, and sixty healthy control group. The average salivary flow rate was calculated as ml/5mint.The concentration of calcium, potassium, and total protein were determined in the salivary supernatant sample. This is done through different biochemical tests. Determination of salivary IgA is done by ELIZA. Results: The most prevalence oral manifestation was dry mouth; there were highly significant differences in salivary flow rate between the two studied groups. There were differences in concentration of total salivary protein and salivary IgA between the two studied groups although statistically non-significance. However there a significant differences in calcium concentration between the two studied groups, also there was a sequential decrease in potassium concentration between the two studied groups and control group. Conclusions: Those type of patients need dental evaluation especially those who are taking radioactive iodine